Timing: Early Autumn (September-November) or mid-Spring (March-April)
When to sow a new lawn
Choosing a seed mixture
There are many different seed mixtures available to gardeners, which can sometimes be confusing. However, always think about what you need from your lawn, in terms of durability and maintenance, and keep this in mind when looking at seed mixtures.
In general, seed mixtures cover these main areas:
General-purpose lawn: This is often a mix of hard-wearing grasses, and is suitable for areas that receive a lot of wear and tear, perhaps from children or pets, or for areas of high traffic. These mixtures will often be a blend of perennial ryegrass, tall fescue, red fescues and browntop. The lawn will usually grow quite fast and will require regular mowing.
Luxury or fine lawn: This is a mix of fine-leaved turfgrasses. These lawns will not tolerate heavy wear and tear, so would not be suitable for children or pets, or areas of high traffic. These mixtures will usually be a blend of chewings fescue, strong and slender creeping red fescue and browntop. The resulting lawn will be very fine in appearance, slow growing and you'll be able to mow at a low height.
Shady lawn: These lawns will tolerate light to medium shade, such as under trees and next to fences or hedges. Most of these mixtures contain hard fescue, strong and slender creeping red fescue and browntop, which are all fine-leaved species. So shady lawns are usually not very hard-wearing.
There are many other mixtures for sale promising 'quick' lawns, 'drought tolerant' lawns, 'easy' lawns and so on, but have a look at the ingredients, and they will usually be very close to those mentioned above.
It goes without saying that you always get what you pay for, and the same goes for grass seed. Unfortunately cheap seed blends are often contaminated with weeds, or contain coarse agricultural perennial ryegrass, not turf ryegrass, meaning you'll get a lawn more suitable for grazing sheep than family barbeques. All you can do to prevent this is by choosing a reputable brand, and reading the ingredients, making sure any perennial ryegrass included is 'turf' or 'fine' ryegrass.
How to sow a lawn
Good seed bed preparation is the key to establishing a successful lawn. Pay particular attention to clearing weeds and cultivating the surface to a fine tilth.
Seed bed preparation
- Eliminate perennial weeds such as couch grass or bindweed well before beginning to prepare the seed bed. Use weedkiller, or hand weed. Do not use residual weedkiller, as it can remain in the soil and will prevent the grass from germinating.
- Dig or rotovate the site to a depth of 20-25cm (8-10in).
- Dig in some well-rotted manure or other organic matter (especially on a sandy soil) to hold moisture. Make sure it is well-rotted, as un-rotted organic matter will cause the soil surface to sink unevenly as it decays.
- After cultivation leave for several days to settle - the longer the better, ideally five to six weeks or more.
- Before the next stage of preparation, remove any weeds that have germinated. Hand-removal is best, or use a contact weedkiller. Do not use a residual weedkiller, as it will prevent the grass from germinating.
- To get the level surface that is crucial for the best lawns, tread the area several times in different directions and then rake several times also in different directions.
- Once firmed, rake several times in different directions.
- Apply and rake in 70g per sq m (2oz per sq yd) of general-purpose fertiliser.
Calculate the correct seed quantity for the area to be sown using the supplier’s recommendation or if unavailable:
- High-quality ornamental turf : 30g per sq m (1oz per sq yd)
- General purpose ornamental turf: 20-25g per sq m (¾oz per sq yd)
- General purpose or utility turf (with rye grass): 15-20g per sq m (½oz per sq yd)
Then sow as follows:
- Divide large areas into small sections, or small plots into square metres or square yards.
- Divide the seed quantity in half.
- Sow half the seed over the whole area by working in parallel rows lengthways.
- Repeat the process with the remaining seed, working in parallel rows widthways.
- If using a seed distributor follow the same method, but calibrate the seed distributor.
- Lightly rake over the sown area to cover the majority of the seeds with soil.
- If the weather remains dry for two or three days, water gently with a light sprinkler.
- If dry conditions persist, repeat watering as necessary while the seeds are germinating and the young seedlings are becoming established.
- When the seedling grasses are about 5-7.5cm (2-3in) high, lightly refirm the soil ideally with a garden roller or the rear roller of a cylinder mower/rotary mower. In the absence of these try carefully treading raised areas.
- Two or three days later, cut the grass down by about one-third of its length. Ideally use a cylinder-bladed mower. Before mowing, remove the front roller on cylinder mowers to prevent flattening the grass. Ensure the blades are really sharp.
- No further mowing is usually necessary for autumn-sown turf until the following spring, but for spring-sown turf, progressively reduce the height of the cut to that suitable for mature lawns, cutting every three to seven days as required.
- Use the lawn as little as possible during the first season. If autumn-sown, try to avoid using it earlier than June and if spring-sown, use it as little as possible up to late autumn.
- During September top-dress with sieved compost to fill in any irregularities.
- There is no need to feed spring-sown grass in the first autumn.
- But do feed autumn-sown lawns the spring following sowing.
Birds can eat seeds and may disturb the seedbed by ‘dust-bathing’. On a small scale, cover freshly sown areas with horticultural fleece or nets which will exclude birds and also improve germination and growing conditions. On a larger scale, try using bird tape which produces a humming noise as the wind vibrates the tape. Alternatively increase sowing rate by 50 percent to compensate for seed losses.
Perennial weeds are best eliminated before and during seedbed preparation. However, some will undoubtedly germinate in the new lawn.
Weed seedlings are usually killed when mowing begins, but the seedlings of perennial weeds are best weeded out by hand using a hand trowel or fork. Coarse grasses may appear in new lawns, and these are best removed promptly, as they can't be killed by lawn weedkillers.
Selective lawn weedkillers should not be used on newly sown lawns earlier than six months after germination. With spring-sown lawns this means not until the following spring as their effectiveness diminishes rapidly with the onset of cooler conditions in early autumn.
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.