Everyone who has a lawn hopes it will grow in quickly with lush results for the summer months, but when the grass grows too quickly, and you can’t keep up with the pace of maintenance, you have a few options to slow the lawn’s growth rate.
Table of Contents
Why Does Grass Grow So Fast In Summer?
Grasses that tolerate drought well tend to be the lowest maintenance lawns, although these are also usually the types that like sunshine. When grass gets a lot of sun, it creates a lot of energy through photosynthesis that can be used for blade and root growth. Grass also tends to get watered more in the summer when there is less rain, contributing to a faster growth pace.
How Can You Slow Down Grass Growth?
The amount of water, nutrients, and sunlight all affect how fast the grass grows; some of these are easier to adjust than others. Choosing a slow-growing grass type is one way to have a low-maintenance lawn, and another option is to use a plant growth regulator, which reduces the vertical growth of grass blades.
Water Less Frequently
When you choose a drought tolerant grass, you can water it less frequently without putting it in danger due to its deep or dense roots that store moisture and energy to handle dry conditions. Summer species like Bermuda, zoysia, and buffalo grass are good choices for drought and sun tolerance.
For shady summer areas in your yard, you can plant a normally cool-season fescue grass. Chewings fescue is a particularly low-maintenance variety, being especially drought tolerant compared to other cool-season grasses.
While some types of grass can be watered less frequently, the rain can’t be controlled. If it’s a wet season, trying to water less won’t achieve the slow growth results you’d like.
Use Less Nitrogen Fertilizer
Grass grows blades and gets its vibrant green color from nitrogen in the soil or from fertilizer. Using less nitrogen fertilizer or slow-release fertilizer can hold back growth a bit, but this balance can be hard to strike since you don’t want to sacrifice your lawn’s lush appearance. It might not be an option to avoid it if the soil is low in nitrogen and needs replenishment.
St. Augustine and fescue grasses are good choices if you have a shaded yard, but it’s difficult and not necessarily desirable to shade your whole lawn to slow the grass’ growth rate.
All grasses need at least a few hours of sunlight a day, so this variable isn’t one that can be controlled well at all. Since most yards are bright, airy, and well-watered, a popular choice to manage grass growth is a plant growth regulator.
Plant Growth Regulators
Plant growth regulators, or PGRs, are organic compounds that plants produce themselves and can be synthesized for turf care to stop grass from growing so fast. When plants grow, their cells divide and build on themselves to make the tissue of the different parts of the plant.
When grass blades grow, the cells extend after division to reach upward. PGRs either suppress cell division or reduce cell extension. Targeting and inhibiting a hormone that supports cell reproduction, Gibberellic acid, is what stunts grass growth.
A PGR growth inhibitor can reduce the growth rate by up to 50% when used correctly. This results in less mowing time, as well as other benefits for your lawn:
- Darker grass color – When grass blade cells and tissue are more condensed from a PGR, the denser chlorophyll may give a more vibrant green appearance.
- Denser blade coverage – PGRs suppress vertical growth but tend to redirect some of that energy to horizontal growth. For spreading grasses, this means denser root, rhizome, and stolon extension, and for bunching grasses, it means more blades sprouted per group.
- Increased stress resistance – When energy is redirected to roots and energy storage, the grass holds more potential to deal with stress, as well as for a growth spurt if use of the PGR is stopped before the natural seasonal slowing sets in.
When Does Grass Growth Slow Down?
When you use a PGR, it will take about one or two weeks to have its effect. It should be applied after the warm-season grasses grow in (late spring), then once every 30 days until two months before frost season.
In northern regions, this may be between the end of May and the beginning of August, with summer season grasses going dormant at the end of September. Warm regions in the south may not be bound by dormancy periods; in which case, regular application directions should be followed.
Plant Growth Regulators interact with the grass’ hormones, so if you don’t apply it correctly, it may not work, or it may stress out the lawn. For this reason, PGR should only be applied during the active growth phase and never too close to dormancy. Reading the labels and instructions for your particular product will guide you to a proper application for your grass type. However, some general rules apply to all types of PGRs:
- Mow before application – PGR should be applied when the grass is at the length you want it and only during the active growing phase. Cut the grass at the beginning of the season a few days before application. If you cut the grass after, the lawn mower can interfere with the process by removing the blades before the product can take hold.
- Less is more – Grass has to get used to the product, so using a little less than the recommended amounts can help you stay on the side of caution. When you use too much, it may result in overregulation, which means growth will be too inhibited. This can result in bronze coloring and weak or worn blades.
- Apply when grass is moist but in dry conditions – PGRs should be applied in the early morning when the grass is dewy or after a light water The slow grow grass spray or granule product must adhere to and sit on the grass blades for 1 to 3 hours to be adequately absorbed. Be sure not to apply before rain or watering, so the product isn’t rinsed off.