“Can wildflower seeds be scattered on grass” is a question we get a lot. Customers usually have an existing grass or pasture that they want to improve. The quick answer is that it’s unlikely to succeed.
Starting from scratch will almost always give you a greater chance of producing a wildflower meadow. On the other hand, if the grass was converted from an old meadow, for example, people are sometimes surprised by the wildflowers that bloom if they leave it unmoved over the summer.
If you choose that method, it’s not always impossible to oversow, but it relies on a number of factors.
Soil Fertility
If you have fertile soil, grasses, or – if not controlled – pernicious weeds will eventually outcompete the wildflowers you’re attempting to grow. It’s tough even if you start with bare dirt, and it’s far more difficult if the grass is already there. It’s not that wildflowers don’t like fertile soils; they just don’t respond to greater nitrogen levels in the same way that grass or plants such as dock or nettle do.
You can acquire a soil test if you’re not sure how fertile your soil is or if it’s alkaline or acidic.
Existing Grass
The grass is so successful because it grows quickly and tends to thatch, thus shutting out any competitors. Some grasses are very aggressive. Lolium perenne, or perennial ryegrass, varieties are particularly popular in grass mixtures.
If you see a sea of these spikelets in the summer, forget about turning your grass into a wildflower meadow! I’m afraid no amount of cautious planning or parasite plants (see below) will help.
You could have some initial success, but in a few years, you’ll be back to see a lot of ryegrass. Other aggressive coarser grasses exist, but PRG is the primary problem, as cultivars are always included in grass or grazing mixtures.
On the other side, you could be pleasantly surprised if you take a close look at your lawn. People frequently discover that they have a variety of wildflowers that they haven’t noticed or that haven’t had an opportunity to bloom. Following the suggestions below will assist them in doing so.
Read also: Do wildflowers need a lot of water?
Preparation
So you’ve got a nice location with what appear to be great grasses. What do you do to get it ready for a wildflower seed mix overseeding?
You’ll need to stomp on the current grass to the point where you can see up to 50% of the ground. You’ll need to use a combination of scarifying and cutting to do this. Cut the existing grass first to break up the thatch.
Then, for bigger sites, use a chain harrow, or a scarifier, spring rake, or hand cultivator, or a scarifier, spring rake, or hand cultivator for a garden. After that, cut it again, this time incredibly short. If you’re fortunate enough to have animals, use them to chop the grass!
You’re attempting to create spaces wide enough for slow-growing wildflowers to establish themselves before being engulfed by faster-growing grass. You could even feel compelled to fully clean little portions to give them the best chance possible.
Seed
If you opt to add wildflower seed, make sure you get it from a trustworthy source and double-check that it not only contains acceptable native species but also that it was grown in the United Kingdom. “Wildflowers” appears to represent different things to various vendors! They must also be freshly collected and well kept.
Although a wildflower-only seed mix will be more expensive than a meadow mix (which includes grasses), you won’t need much; plan on 1g per square meter.
If you’re sowing in late summer or early fall (the best period), put Yellow Rattle, Rhinanthus minor, in your mix. If it doesn’t, it’s usually worth purchasing a small amount to add. Because the seed has a limited vitality, if you sow it in the spring, you should add it the following September.
You might decide it’s all too much at this stage – especially if you just have a tiny space – and replace it with some plug plants. They are more costly and provide less variety, but they are a viable choice. Calculate 5 per square meter, and a single tray will cover 25 square meters.
Read also: How to Grow Wildflowers Indoors
Seeding
…is straightforward. Because the seeding rate is so low – roughly 1g per square meter – you’ll need to mix your seed mix with some peat-free compost or sand halfway through planting to avoid running out of pricey ammo. It makes no difference what the ratio of inert carrier to seed is.
If you’re seeding a huge area, use canes to divide it into squares. If you have a 5mX5m square, you’ll need roughly 25g of seed to cover it.
Distribute equally throughout the area to be seeded. If possible, make two passes, one from left to right and the other from front to rear.
If possible, give the area a light roll after seeding to ensure the seed is in excellent touch with the ground.
Initial Management
Keep the freshly planted region clipped to roughly 3cm for 6 months following sowing if you can stand it. This will protect the grass from overpowering the wildflower seedlings. Only if your wildflower seed contains cornfield annuals such as poppies should you clip them before they finish flowering.
This regimen will also help reduce weeds, but if you notice plants like dock, remove them immediately!
