Using yellow rattle to increase species diversity

Yellow rattle is an attractive, semi-parasitic, grassland annual. In the past this plant was a serious pest for farmers as it weakens grasses and as a result can reduce hay yields by as much as 50%. In a landscape or garden context however, this suppression of grass growth is welcomed as it produces a better display of wild flowers and eases the mowing required.

Yellow rattle germinates late February to early March, flowers in June, and sets seed in July. At the end of each growing season as the annual yellow rattle plants die away they leave behind gaps into which new wild flowers can establish. As a result, wild flower seed sown into an existing sward will establish more readily in areas where yellow rattle already does well.

For a description of the plant and to order seed go to the yellow rattle species page.

Getting yellow rattle started

Yellow rattle establishment can be unpredictable and plant numbers may take two to three years to build up, this will depend upon the sowing rate chosen, and site conditions.

For good results, the following points are essential:

Site Selection

  • Yellow rattle will not thrive in all grassland. The most suitable sites for yellow rattle will be managed grassland of low to medium fertility that contains a balanced sward of finer grasses not dominated by coarse or vigorous grass (ryegrass, cocksfoot, tall oat-grass or couch). Grassland that is the result of sowing a meadow mixture will have suitable grasses, as will finer turf in gardens and meadows. Yellow rattle often fails to take in ryegrass leys and neglected, over-grown or tussocky grassland.

Preparation

  • Cut or graze the sward in the autumn, aim to keep the grass short (40-50mm). Graze or mow before and after seeding as needed.
  • Create gaps across the site with exposed soil for yellow rattle seed to germinate in. This can be achieved by autumn/winter grazing with stock (their hooves open the sward), or mechanically by harrowing or raking, aiming to expose up to 50% bare soil.

Sowing

  • Timing: yellow rattle seed must be sown in the autumn as it needs prolonged chilling through the winter to trigger its germination the following spring.
  • Sowing rate: yellow rattle seed should be scattered onto the prepared surface at a rate of 0.1 to 1 g/m2.

Yellow rattle may be sown as a component of meadow mixtures on to a prepared seedbed. First year meadow management (mowing) can compromise seed set of yellow rattle. To be sure of getting yellow rattle in the second year, it is best to re-sow yellow rattle in the autumn of the first year (as above). Where cornfield annuals have been sown as a ‘nurse crop’, yellow rattle has more opportunity to self-seed.

Aftercare: Managing swards for yellow rattle

Yellow rattle is an annual with short lived seed which needs a chance to set seed each year. Cutting or grazing between April and mid July will eliminate yellow rattle by preventing it seeding and should be avoided. Traditional meadow management based around a late July hay cut provides yellow rattle with the opportunity to set seed and for the seed to scatter during the process of haymaking.

Autumn grazing, or mowing and harrowing, is also important each year as it will help to keep the sward open. This is important in providing new sites in to which yellow rattle can establish the following spring. Yellow rattle populations tend to fluctuate in meadows and often ‘move’ about from year to year as a reflection of the balance of health of the yellow rattle plants and their host plants in any one patch.

Yellow rattle will parasitize many flower species, not just grasses. It would appear to be opportunistic in selecting the more vigorous components of a sward which is often the grasses and clovers. Concern is sometimes expressed that very successful yellow rattle populations can have a negative effect on the composition of a meadow. Our advice is that as with most semi-natural grassland communities containing yellow rattle a balanced equilibrium will usually establish itself over time. If deemed necessary however, yellow rattle can be reduced or eliminated by mowing to prevent seeding for one season.

Yellow Rattle
Rhinanthus minor

Other Names: Rattle Box

, Hay Rattle, Hay Shackle

Distribution: Widespread throughout Britain.
Habitat: Pastures, meadows and short turf.
Description: Native annual of medium height (up to 60cm) with golden yellow flowers from May to July.
Uses: Yellow Rattle is a useful plant to introduce when creating a wild flower meadow. It is semi-parasitic on the roots of plants, especially grasses, and once established will reduce the vigour of the original grass by up to 50%. It fixes its roots onto the root system of an adjoining grass, extracting water and minerals from it. All ancient meadows have this plant.

Sow at the rate of 1g per square metre if combined with a meadow seed mix.

Sowing Instructions for Seeds: Yellow Rattle needs a period of cold to germinate successfully, so is best sown between August and December. Yellow Rattle is an annual and so if used in a meadow, it is best to cut the meadow after the rattle has had a chance to seed ie after the end of July.

If sown into an existing meadow, ensure that the grass is cut very short (an inch or less) and create areas of bare soil by scarifying, harrowing, raking etc. You should aim to expose up to 50% bare soil. Sow the seed onto this bare soil and ensure good contact by rolling or treading in.

Our plants and seeds are of native British origin. Please note: small quantities of grass seed may also be present.

Fresh Yellow Rattle seed is available from August to December. Fresh seed needs to be sown immediately and will have a higher success rate than seed which has been dried for longer.

If you would like to be contacted when the fresh seed is available, please email [email protected] If you would like to order Fresh Yellow Rattle seed, click on the link below:

Fresh Yellow Rattle Seed

How to create a wildflower meadow using plug plants

Plug plants are ideal to use in smaller areas to create a mini meadow; so ideal in a garden, community area or existing grassland/ lawn.

Use of plug plants

Plug plants are small plants which are ready to plant out. PlantWild plugs are larger than most; please click here for image, and they will start to flower in the first spring or summer after planting. We recommend up to 5 plug plants per m2. They can be planted out in Spring or Autumn and can go into bare soil if wildflower seed is being sown or they can go in later, once the seed has started to establish. Alternatively the area can be planted entirely with plug plants.

Plug plants are also ideal to plant in an existing grassland or in a lawn where they can be planted in Autumn or Spring providing the sward is cut very short when they are planted. the grass cuttings should be removed before planting, to ensure nitrogen levels are reduced. In a lawn it is preferable that the lawn has been left unfertilised for several months, and in a grassland, any perennial weeds should be removed as detailed below in the site preparation tips. Plug plants are also perfect to create a focal area in a large area of meadow, where specific wildflowers can be chosen to complement the plants that are present already

Competition from surrounding grasses can be reduced by digging out small circles of grass before planting, or in a short lawn they can be planted directly into their chosen site. If vigorous grasses are likely to be an issue then it is recommended to include Yellow rattle which is a partial parasite of grasses and will keep their vigorous growth in check. Although Yellow rattle is an annual it will self seed when the area is cut from July on wards.

It is a good idea to plant plugs in groups of at least 5 of the same species. This gives a natural look and helps pollinators locate the plants when they flower, and helps them to establish over time to give a higher impact. They can be planted with a small trowel or a dibber , adding some peat free compost to the planting hole and should be watered well to prevent then from drying out until they are established. Following which, through the growing season the wildflower plug plants should compete favourably with any fine grasses that are present. The first cut of the area would not be required until around mid July, although this would also be dependant on the flowering time of the plug plants. (see the meadow maintenance article here)

Rabbits also enjoy plug plants! If you have a lot of rabbits please protect the plants with fencing, mesh or thorny twigs.

If you would like help choosing your plug plants for your meadow ; why not choose the meadow plug plant collection, or do get in touch and we will be happy to discuss your project!

Site preparation

A suitable site for a wildflower meadow has full sun, fairly low fertility and few perennial weeds. If possible the chosen area should be surveyed to establish the flora already present to make sure you are not destroying an area already rich in biodiversity. Also the nutritional condition of the soil and the soil type should be considered. Ideally any wildflowers chosen should be compatible with the soil conditions and preferably be of local origin.

On existing grassland it is beneficial to identify the grass species present if at all possible. This is most easily done in summer when the grasses are in flower. If the grasses are fine-leaved, short (up to 70cm including seed head) and include species such as Meadow foxtail, Common bent, Sweet vernal grass, Yorkshire fog and Crested dogstail, then the grass can be left and diversity increased by the addition of plug plants . If the grasses present are tall, wide-leaved, clump-forming or form a thick, dense thatch, e.g. couch grass, Deschampsia or a grazing mix rich in rye grass, the turf should be stripped off, ploughed in and plug plants (or seed) sown into the bare soil.

Weeds

It is likely that a lawn or garden would have few weeds, and any that are present can easily be located and removed by hand.

However in other larger areas, if perennial weeds are present such as docks, creeping thistles, brambles and nettles, then these are an indicator of fertile soil and their seeds can lie dormant in the soil for many years. Therefore, to remove areas of these weeds it is well worth devoting an entire growing season to eradicating weeds before planting in the Autumn. The site may be ploughed and cleared with 1 or 2 applications of weedkiller. A spot weedkiller would be preferable to target the troublesome weeds, although no planting should commence until at least 6 months after the last application. However, the chemical-free method is to spread black plastic mulch over the area for at least 6 months before sowing or planting, or even to hand dig the weeds. If there are buttercups present, it is beneficial to identify the species if possible: creeping buttercup is an invasive weed, whereas meadow buttercup is a meadow flower, and can be left to grow as part of the meadow mix.
After eradication of the weeds it is recommended not to plough again or cultivate deeply as this will raise another batch of weed seeds to the surface. Instead,cultivate the top couple of inches of soil to create a firm, fine seed bed.

If the plan is to plant on a bare soil site where perennial weeds are not a problem e.g an arable field, it is still advisable to cultivate some weeks or months before planting, to ensure weed seeds germinate and if so they can be hoed out before planting. If the common arable weeds such as fat hen, sow thistle, red deadnettle appear in the first year, they are not an issue as they are annuals or biennials and are not going to be a long term problem. They can be cut to prevent seed setting and they will soon die out from the meadow as it evolves.

To maintain your meadow please see our additional page with advice on maintaining your meadow.

Yellow Rattle (Hay Rattle) plant plugs

Also known as Hay Rattle, this pretty wild flower attaches to grass roots and suppresses their growth enabling wild flowers to flourish in grass lawns and meadows.

Pre-orders now being taken for delivery mid April 2020. You can buy Yellow Rattle seed via the yellow link further down this page.

The plant plugs here come supplied with host grasses within the plug cells so you can also grow them in flower beds.

Wild flower plant plugs are little plants ready for you to plant out in the ground and are a great alternative to using wild flower seeds if you wish for quick results. These pretty yellow wild flowers do a great job weakening and reducing grass competition for wild flowers in open lawns and meadows. They are annuals and flower throughout the spring and summer and look lovely. Their dry seed pods rattle, hence their name. They shed their seeds from July, which germinate in the spring and become new plants for that year increasing the quantity of plants and the grass suppressing effects for your grassland.

Yellow Rattle plugs will be available from late March to late May when they should be planted straight out into your lawn or meadow; cut your grass low first and remove the cuttings before planting. Stocks do run out fairly quickly in the spring and so advance ordering is a good idea.

Yellow Rattle seed is also available which is useful for larger areas. To view this .

For something nice to surround your wild flower area click here to see my ‘fencing’

I have just rattled off a stiffly-worded email of complaint, for it has just dawned on me that it is now over a month since my lawnmower went in for repairs at the local garden machinery workshop.

I have started converting a number of areas of lawn in my garden to flower-rich meadows, and my mower simply isn’t designed for such work. I have let the meadow plants grow, flower and seed, and the resulting foot-high herbage is overpowering my machine. Wild flower meadow creation is not proving to be the walk in the park as described by the magazines.

Problems aside, the developing grasslands have given me a great deal of pleasure. In an earlier posting I have mentioned the flourishing bee orchids that occur naturally in the lawns here, but more exciting still has been the appearance of a single flowering early purple orchid in a spot in which I scattered seed roughly four years ago. Another native beauty present is the greater burnet saxifrage (Pimpinella major), something of a local speciality here to the east of Plymouth, and notable for its airy stems of queen anne’s lace flowers that are so flawlessly white they gleam in the dark. And, of course, these flowers have attracted a wealth of insects: brown and blue butterflies in abundance, and bees galore.

But one thing has outshone everything else, and that has been the yellow rattle (Rhinanthus minor). I love this plant for its strongly architectural structure and its burnished golden flowers, which look like tiny turtles hatching from their eggs. The plant has a more practical use, too, for it is a “hemi-parasite” – a partial parasite – and can be used to reduce the vigour of meadow grasses. Sure, it produces green leaves that photosynthesize, generating energy for plant growth from the sun’s ray, but the rattle is happiest when its roots lock onto those of the grasses and suck the life out of them. Even out of flower, areas of meadow heavily invaded by this species support only the most meagre growth of grass: little wonder yellow rattle is loathed by farmers.

It is loved, however, by those keen to establish a meadow grassland rich in flowers. It’s important to reduce competition from coarse growing perennials, grasses included. This can be done by stripping nutrients from the soil – for example, by scraping off the overlying topsoil to reveal the poorer subsoil beneath – but yellow rattle achieves much the same results at considerably less cost and effort, and has become a mainstay within wild flower seed mixtures.

If you want to introduce this species into your lawn, it’s worth understanding the plant’s ecology in the wild. It is an annual species that germinates in spring (typically March), flowers at the height of summer, and is in full seed a couple of months later (say, late August). As a strictly upright plant it cannot tolerate being cut or grazed off too severely during this period, so is most at home in old-fashioned hay meadows, where grazing is excluded during the summer months, and a late hay cut allows a good proportion of flowers to have successfully set seed.

First cut your area of grass – think more of shaving a head to control nits, rather than a short back and sides – and collect and dispose of the clippings elsewhere. Sprinkle seeds very thinly over the scuffed turf: even a seed or two per metre is ample, for if the introduction is successful, the resulting plants will shower the ground with an abundance of fresh propagules within the year. The seed is apparently short-lived, so sow it fresh in the late summer or autumn, and no later. You can cut as short and as often as you like through the winter and into spring, but by March, stop cutting, or at least raise the mower blades, for the seed should be germinating by then. You can probably get away with a final cut into early summer if you set the mower blades at their highest setting, for the youngsters will simply be encouraged to form a strong bushy plant if decapitated in their first month of growth.

However, by mid May all mowing should cease, to allow the rattles to flower and seed. You’ll know that the plant is mature and shedding ripe seed when the fruits take on a ghostly silvery-grey colour, and rattle when shaken: at this stage it looks rather like a poor man’s honesty.

Don’t be too hasty to cut and remove the rattle-rich hay for the fruit ripens over a period of weeks, but when most of the seed heads have turned grey, it is a good time to pull up bunches of the plants, and to shake them over new lawn to encourage the large disc-shaped seeds to fall. With the last seed successfully shed, it’s time to start that heavy mowing again. Which is, of course, why my mower is now struggling! Next year, I am going do my big end-of-year cut with a strimmer, and then rake and collect the cuttings by hand, before bringing out the mower.

Yellow rattle seed is widely available to buy, but do check with the supplier that the seed is of local provenance. Six loosely defined subspecies of yellow rattle occur across Britain, reflecting differing geologies and habitats, so it would be tragic if we upset this balance through the introduction of non-native stock from the continent. Better still, you won’t do any harm by taking just the smallest handful of seed from a natural population growing in a meadow close to your home, and use this to start your garden colony. Do make sure that you are removing only the tiniest proportion of seed from the wild colony, and check that the landowner is happy.

Andy Byfield is one of the founders of the wild plant charity Plantlife.

• This article was amended on 3 July to correct the image credit. The photographer is Jonathan Buckley.

  • Position: full sun
  • Soil: moist but well-drained soil soils including chalk
  • Rate of growth: average
  • Flowering period: May to July
  • Hardiness: fully hardy (annual)
    This is an extremely beneficial annual for the wildflower meadow. It is semi-parasitic and takes its water and nutrients from neighbouring plants – particularly grasses. Therefore it is useful in maintaining just the right balance between wildflowers and overly vigorous grasses, which might otherwise take over completely. It is an attractive annual, with vibrant yellow flowers that provide summer colour and papery seedpods that rattle when the seed is ripe.
  • Garden care: In autumn find a sunny spot with established grass or lawn (if you are trying to convert it to a wildflower meadow) that has been cut back to 4-5cm high. Scarify the soil with a wire rake opening up a few bare patches and scatter the seed onto this. Keep the grass short over winter and the seed will start to germinate in spring. Once established it self-seeds freely, but cutting it back before it flowers will prevent it coming back in subsequent years. Sow at 0.1g – 0.5g per sq m.
  • Sow: August – November
  • Flowering: May – July
  • Approximate quantity: 50 seeds

When it comes to germination, some samples of all eight species were very poor, with low or even zero viability (and hence germination). The common corn poppy was especially bad, with many very poor samples, and even the best managing only about 60 per cent germination. But once again the species that stood out was yellow rattle. Some samples were really good, but many were not, and in three out of 17 samples, all the seeds were dead. We don’t know why yellow rattle viability was so poor, but it turns out that harvesting has a bearing on seed quality.

In four species it was possible to compare samples from multiple hand harvests with those from a single mechanical harvest. The former were consistently better, sometimes dramatically so, although it’s not possible to pin down precisely why. Multiple hand harvests may just produce better seeds, perhaps because mature seeds are actively selected. But it’s also possible that seeds were damaged by the process of mechanical harvesting itself. Whatever the cause, it looks like you get what you pay for: the expensive, hand-harvesting option produces better seeds.

When we’re all being advised to add yellow rattle to wildflower meadows to help control the vigour of grasses, it’s clear that the quality of commercial seeds is unacceptable. One option, which I adopted when I established yellow rattle in a meadow in my old garden, is to collect your own from the wild. You don’t need many seeds for this; yellow rattle is an annual, and as long as it’s happy in your meadow, the size of your yellow rattle population will very soon be determined by the number of seeds produced the previous year, and not by the number you started out with.

Finally, always remember that yellow rattle seeds need a long period of cold to break dormancy, so always sow them as soon as they’re ripe. And don’t cut your meadow until the ripe yellow rattle seeds have been shed.

Ken Thompson is a plant biologist with a keen interest in the science of gardening. He writes and lectures extensively and has written five gardening books. The most recent is Where do Camels Belong? The Story and Science of Invasive Species.

Kew Species Profiles

General Description

This pretty little annual sends out roots that grow into the roots of neighbouring grass plants, and steal nutrients from them. It will produce many tiny seeds that rattle around in the papery brown calyx – hence the common name – and it can spread itself year by year, weakening the poor, hard-working grasses that it grows among! But you can get rid of it easily: just cut the flowers before they can produce seed, and the yellow rattle will disappear from your meadow. But if you like variety in your field, keep the rattle; it will weaken the grass, giving other species more chance to survive.

Species Profile Geography and distribution

Found in Europe, Russia, western Siberia, northern USA and Canada.

Flowering head of the yellow rattle Description

An annual herb, 15-50 cm tall, with roots that penetrate the roots of other plants. The toothed leaves are borne opposite each other on the stem. The flowers are borne above the leaves, and are small and yellow, just peeping out of the inflated green calyx. The calyx turns brown in fruit, and holds the rounded capsule in which the seeds rattle about – hence the common name. Yellow rattle flowers in summer and is pollinated by bumblebees; if that fails, it can fertilize itself. Several varieties have been described, but are now all thought to be part of a single, variable species.

Threats and conservation

Rhinanthus minor is a widespread species, and is currently not under threat. Changes in farming practice will influence this plant; you will not find many in ‘improved grassland’, but in nutrient-poor, low-lying fields, yellow rattle can be very common.

The conservation of a parasite may not immediately strike people as important. However, recent studies on the impact of R. minor show that annual parasitic plants can play an important role in maintaining species diversity within habitats through differential growth suppression effects and enhanced soil nutrient recycling.

Uses

Yellow rattle is hemi-parasitic on grasses, that is, it can survive independently – but it grows best when drawing some nutrition from the grass roots its roots penetrate. Farmers used to dislike it, as it weakens grass, and it was seen as an indicator of rather poor grassland. But for this very reason it is now used when trying to turn grassland into wildflower meadows. This is done by sowing yellow rattle seeds in the grass. Because they steal food from their neighbours, yellow rattle seedlings can grow very quickly in the spring and also slow the growth of the neighbouring grass plants, so other plants have more chance to survive.

Millennium Seed Bank: Seed storage

Kew’s Millennium Seed Bank Partnership aims to save plant life world wide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.

Description of seeds: Average 1,000 seed weight = 2.51 g

Number of seed collections stored in the Millennium Seed Bank: 12

Seed storage behaviour: Orthodox (the seeds of this plant survive drying without significant reduction in their viability, and are therefore amenable to long-term frozen storage such as at the MSB)

Wildflower meadow restoration

Yellow rattle seeds were sown alongside Kew’sMillennium Seed Bank atWakehurst in the summer of 2009, as part of work to restore wildflower meadows. The seeds need a long cold period to germinate, and the harsh winter provided the perfect conditions for the plant to flourish and there is now an abundance of the delicate yellow flower, along with other wildflowers such as ox-eye daisy.

Andy Jackson, head of Wakehurst, said: ‘The plant is called the yellow rattle because the seeds are held very loosely in a papery cup, and when they mature – which we expect to be around mid-July – they actually rattle’. He added: ‘The irises and the yellow rattle are just two of the huge variety of different flowers which will be providing a wealth of colour and natural beauty at Wakehurst this summer’.

Yellow rattle at Kew

Wildflowers, including yellow rattle, can be seen growing alongside Kew’s Millennium Seed Bank at Wakehurst in the Loder Valley.

Distribution Canada, USA Ecology Grassland. Conservation Rated as of Least Concern (LC). Hazards

Rhinanthus spp. are reputedly poisonous to livestock and are usually avoided by grazing animals. The seeds contain iridoids which used to be found as toxic contaminants in bread cereals.

Yellow Rattle

Yellow Rattle (Rhinanthus minor) Seed

Yellow rattle (Rhinanthus minor) is an attractive, partly parasitic (“hemi-parasitic”), annual wildflower of short grasslands. “Partly”, because it photosynthesises. It’s part of the Figwort family, and used to be widespread across the UK on mostly neutral soils. Although it’s still found across the country, including in the Machair, it’s now much less common. It’s appearance is variable; we think there are at least 6 sub-species of it in the UK.

Once Yellow rattle is established it can reduce the vigour of many grasses by up to 50%, thus benefiting other sown wildflowers – check out our blog on how to grow and manage it. Once it dies back, each Rhinanthus plant leaves a space for wildflowers to fill too. It does need full sun, however, and even Yellow rattle will be shaded out by more vigorous grasses on fertile soil – it’s not the key to all a meadow maker’s problems. Having said that, it can work brilliantly in helping to bring wildflowers back into old pasture, although of course it doesn’t of itself reduce soil fertility. Yellow rattle also has other unexpected results. For example, ribwort plantain has learnt to retreat away from it, so does tremendously well in swards with a lot of Rhinanthus in as it fills in the space it leaves behind. Clever things, plants.

Rhinanthus is a helpful plant for pollinators too, particularly bumblebees and butterflies, although honeybees find its slightly complicated flowers difficult to access.

Rarity

For obvious reasons farmers were never terribly keen on Yellow rattle, although it’s apparently tasty for livestock. That said, as it is an annual it’s easy to mow out before it sets seed (when it rattles) in July. This was traditionally time to cut the hay; hence its synonym, “Hay Rattle”. Its seed has notoriously short viability – you must sow from this season’s harvest. It will also disappear in thick, unmanaged sward. The seeds are small and the plants unable to compete with surrounding vegetation early on. Nowadays, silage cuts over the summer stop it from seeding at all. Needless to say, it’s much less common than it used to be a hundred years ago.

Appearance

Yellow rattle seeds are light flat discs, designed to be wind blown. They germinate in January and the seedlings become evident in early March, so that they steal a march on the surrounding grasses. Be careful not to mow them out! Once they’ve got going they are easy to spot, however. The leaves have serrated edges, a bit like a nettle, and in seedlings look rather stiff. The flowers look a little like yellow snapdragons (or little cockscombs, apparently). They’re very pretty. The plants grow to around 50cm tops.

Buying

Yellow rattle seed must be sown from summer to the year end, as it needs to be chilled to trigger its germination the following spring. We recommend adding the seed to a newly established meadow after its first season. As it doesn’t last the seeds need to be as fresh as possible. It also reacts badly to being badly handled – it’s tricky to process properly. You need to be careful where you source it from. Our Rhinanthus seed is freshly harvested from meadows around southern England. We test it once it has been harvested and cleaned to check on the seeds’ viability. We don’t store it for longer than 12 months.

Sowing Seed

The time to seed Yellow rattle is between harvest and the end of December. Like some other of our wildflower species, it needs to get cold to trigger germination – “vernalization”. Sow by hand onto existing sward, at a rate of up to 1g per square metre. It’s expensive stuff, so you might want to use a lower rate or just seed some areas and wait for it to spread. It’s really important that the existing grass is cut VERY short before seeding and, if necessary, chain harrowed or scarified to get rid of any thatch. Ideally you should see 50% earth. The seeding rate is very low, so you might want to add sand or similar to bulk it out. Once sown, either walk or lightly roll in, or use livestock to tread in the seed and make sure it’s in good contact with the earth.

Management

Yellow rattle is a plant of short grassland – if the grasses surrounding it are allowed to grow long and rank it won’t be able to compete. Once you’ve taken a hay cut, typically from July to late August, it’s important to keep the grass lightly grazed or cut (removing cuttings) over the winter. Stop cutting in March, or you’ll chop the heads off the young seedlings!

Our Seed For Sale

Yellow rattle seed may be ordered in 0.1 kg increments from 0.1 kg upwards. Quantities up to 10 kilos at the kilo rate, thereafter prices on request. We also now sell smaller quantities at our sister website: BritishWildflowerMeadowSeeds.co.uk.

The seed we sell is always from the current harvest, and is carefully processed to avoid damage and low germination.

Your purchase helps us support a range of charities, which are related to the products we sell.

We strongly recommend reading up on meadows before buying Yellow rattle seed. Although our Rhinanthus seed has high germination rates, you need to be careful about initial care and establishing an annual regime. Don’t be put off though – once you get the hang of it it’s pretty straightforward, so long as you follow instructions!

How to grow Yellow Rattle (Rhinanthus minor)

  • Even better, if you know someone that has yellow rattle in their meadow (maybe a local nature reserve or farmers’ field) ask if you can collect some seed. Collect seed from June to August by picking a few stems on a dry day and shaking them into a paper bag.
  • Allow a small handful of seed per square metre, but remember you only need a few plants to grow in the first year – they’ll produce much more seed for you in following years.
  • How to: sow the seed

  • Cut your grass as short as you can between July and September and remove the hay or clippings. Then remove the thatch (the layer of dead grass and moss that builds up on the soil surface) to expose some bare soil, using a rake or harrow. This ‘scarification’ is really important; the seed must to be able to reach the soil surface. Aim for at least 50% bare soil, preferably more.
  • Sow by hand straight away, scattering the seeds on the soil surface. This must be done by November as the seeds need about 4 months of temperatures dipping below 5oC in order to germinate in spring. Seed sown after Christmas germinates poorly.
  • If you’re sowing an entirely new meadow in an area of specially prepared bare soil, sow the yellow rattle along with all the other seeds in the autumn.
  • How to: keep yellow rattle going

  • Seedlings will begin to appear in spring, from late March through to May. Don’t be worried if only a few plants germinate in the first year. They’ll grow and shed their own seed and numbers should increase rapidly.
  • From now on you don’t need to scarify the soil each year, just cut the meadow really hard once the seed has been shed and remove the hay or clippings. This can be any time from late July or preferably into August or early September, allowing late-blooming plants to provide food for pollinators and shed their seed.
  • Aim to get the grass sward below ankle height. In agricultural settings, grazing the meadow hard now with cattle or sheep until New Year (if it’s not too wet) is very beneficial. In a garden setting, cut the grass (and remove clippings) once or twice again before Christmas.
  • If your soil is very fertile you might struggle to keep yellow rattle going – it can slowly disappear. Always create meadows on poor, infertile soils.
  • Part of the joy of creating a wildflower meadow is seeing the gradual changes over time. As yellow rattle establishes, the grass will become thinner and plants like oxeye daisy, knapweeds and vetches will start to appear. Eventually, if you’re lucky, even a few orchids might find a home.

    It’s a long journey, but it starts with yellow rattle.

    Yellow Rattle or Hay Rattle (rhinanthus minor) is partly a parasitic species that draws some of its nutrients though the roots of grasses and is frequently used to increase bio diversity in wild flower meadows. Its parasitic nature suppresses the growth rate of grass, which in turn can make conditions more receptive for the establishment of other wildflower species. Used correctly it can reduce grass growth very successfully and once established can often spread to other areas within the meadow.

    Sowing Yellow Rattle seeds

    There are 4 basic rules to follow when sowing Yellow Rattle, which are as follows,

    1. Seed should be as fresh as possible.

    2. Seeds should always be sown into existing grass or along with meadow grass seed.

    3. Sowing should ideally be performed in the autumn and before the end of December. This is because Yellow Rattle seeds require a special treatment known as stratification or vernalisation. Essentially this means that seeds require a period of prolonged cold to trigger germination. If it is not possible to sow seeds before mid winter then we recommend that they be placed in refrigeration for about 5-6 weeks instead.

    4. Cut grass as short as possible before sowing. Broadcast seeds evenly over the plot on a calm day. After sowing, roll or scarify the seeds into the surface of the soil.

    Identifying Yellow Rattle seedlings

    Given suitable conditions, Yellow Rattle seedlings usually emerge in February or March following an autumn sowing. They have small but distinctive leaves with toothed edges which develop rapidly (See photo below). If possible it is important to identify the Yellow Rattle plants as early as possible in order to manage them correctly.

    Yellow Rattle seedling

    Managing Yellow Rattle

    Yellow Rattle is an annual plant so has to be managed carefully for it to successfully self-seed. If the meadow is cut too early the plants can be damaged and will fail to flower and produce seed. In meadows that already contain other wild flowers in addition to Yellow Rattle, traditional advice is to perform several spring cuts, which can lead to problems if the cutting height is too low. The secret is to identify the Yellow Rattle seedlings as soon as possible and ensure that patches are either avoided or cutting machinery is set to a greater height than that of the Yellow Rattle plants. Similarly, if the Yellow Rattle meadow were grazed, then it would make sense to fence off areas with plants and remove livestock during the critical period between March and July.

    Flowering

    The flowering period of Yellow Rattle is quite short and usually peaks in June. Plants are normally about ankle height and produce a mass of small Yellow flowers, which carpet meadows in early summer and attract bees.

    Yellow Rattle in full flower

    By July most Yellow Rattle plants have died back and quickly turn brown, leaving a distinctive and attractive papery seed head.

    Yellow Rattle seed-heads

    In a stiff breeze the seeds may be heard rattling inside and this is indeed how the plant acquired it’s name.

    The light brown seeds are also quite distinctive (see photo below) being relatively large and flat. By the end of July they will have fully ripened and the sward can safely be cut or grazing resumed.

    Yellow Rattle seeds

    Buying Yellow Rattle seeds

    As mentioned above it is important to buy Yellow Rattle that is as fresh as possible. Typically, freshly harvested seed becomes available in August or September so the perfect time to purchase the seeds is in autumn. We anticipate having 2015 Yellow Rattle available shortly following successful harvest. We recommend early ordering as Yellow rattle seed is always in high demand, especially for wild flower mixtures and can sell out rapidly, with prices increasing as the season progresses. Please to order Yellow Rattle seeds and view further videos of Yellow Rattle in its various stages of growth.

    UPDATE 25.07.2015 Fresh Yellow Rattle seeds have just arrived and are available for immediate dispatch.

    Leave a Reply

    Your email address will not be published. Required fields are marked *