Kentucky Bluegrass requires at least 1 inch (2.5 cm) of water per week during the growing season. In temperatures above 75℉ (24℃), 2–2.5 inches (5–6.5 cm) of water should be provided.
Water your Kentucky Bluegrass deeply and infrequently. Watering should be done once or twice per week. When increasing water for your lawn, lengthen your watering sessions but do not exceed 2 watering sessions per week. Deep, infrequent watering promotes grass health and encourages shallow-rooted Kentucky Bluegrass to form deeper roots and resist drought.
How to Water Kentucky Bluegrass
The watering needs of established Kentucky Bluegrass depend on the time of year. During spring and fall, when temperatures are cool, provide 1–1.5 inches of water per week. This can be done with a once-weekly watering session. 60–90 minutes with the sprinkler should be enough.
- Provide Kentucky Bluegrass with 1–1.5 inches (2.5–4 cm) of water per week during the spring and fall.
- Increase watering to volume 2–2.5 inches (5–6.5 cm) during summer, when daytime highs regularly exceed 80℉ (27℃).
- 1 hour with a sprinkler usually provides 1 inch (2.5 cm) of water.
- Water in the early morning (5–7 AM) for best results.
- When Kentucky Bluegrass is dormant (brown) in winter, little to no watering is required.
- I love the customizable coverage areas my Melnor sprinkler provides for my lawn.
During peak summer temperatures, Kentucky Bluegrass will go dormant if it is not adequately watered. As summer approaches, increase watering to 2–2.5 inches (5–6.5 cm) of water per week. Provide this via 2 weekly sessions that each deliver 1–1.25 inches of water.
I have personally found that using a Rain Bird watering timer is the most consistent way to get enough water, especially if you aren’t home.
- Advanced Scheduling: This easy-to-use 7-day digital timer is ideal for use with hose-end sprinklers, drip irrigation, and soaker hose, allowing you to program up to two watering times per day, any day(s) of the week.
- Flexible Watering: It's perfect for watering all areas of your yard, including gardens, landscaping beds, and both newly seeded and established lawns, with a working water pressure of 15 psi (minimum) – 90 psi (maximum).
- User Control: Instant override buttons for Rain Delay (cancel watering) and Water Now (manual watering) provide full control, while the device displays program status such as the next scheduled cycle and time remaining on the current cycle.
How to Water Kentucky Bluegrass Seed
Newly planted grass seed, like Bluegrass, has different watering needs than an established yard. If you have just spread Bluegrass seed, here’s how to water it to make sure those seeds sprout and spread to fill your lawn.
- Water the soil for 30 minutes before seeding, to moisten the area. If the lawn is flooded, there is too much irrigation.
- After seeding, immediately water your lawn for 5–10 minutes. This will moisten the Kentucky Bluegrass seed.
- Water your grass seed two times per day (morning and afternoon) for 10–15 minutes per watering session. Continue this for 21 days.
By keeping the soil moist from the time you seed until those Bluegrass seedlings are standing about an inch above the soil surface, you encourage the highest germination rate. After your seeds have sprouted, gradually reduce the watering to once per day, then once every other day, until you reach a standard watering schedule.
How Long Can Kentucky Bluegrass Go Without Water?
Kentucky Bluegrass can survive 4–6 weeks without water during the growing season. However, this is not advised. Kentucky Bluegrass that experiences drought will immediately begin to go into dormancy. It will turn brown. From there, grass left unwatered may die within a month.
- Kentucky Bluegrass is not a drought-tolerant grass. It can die within 4 weeks if unwatered during the summer heat.
- Kentucky Bluegrass has shallower roots than other turfgrasses, meaning it cannot reach deep water reserves and survive drought.
- If your Kentucky Bluegrass begins to turn brown during the growing season, increase irrigation immediately.
Although your Bluegrass can survive drought, it’s a serious setback for your lawn. Drought-stricken Kentucky Bluegrass will grow more sparsely and will be more susceptible to weed invasion. Summer heatwaves can be dangerous for Bluegrass lawns, so keep your eye on your lawn at this time and increase irrigation as needed. If your lawn is losing its green color, it’s a sign of trouble.
Can You Overwater Kentucky Bluegrass?
Like any turf grass, Kentucky Bluegrass thrives in moist soil but can be killed by swampy conditions. Overwatering is just as dangerous as underwatering, and brings with it a host of problems.
- Overwatering invites pests and diseases that can kill Kentucky Bluegrass
- Avoid watering daily or providing more than 2.5 inches of water per week.
- Reduce watering as temperatures drop after the summer peak.
By adjusting the watering volume according to the season, you can prevent overwatering your Bluegrass.
What Does an Overwatered Kentucky Bluegrass Lawn Look Like?
Sometimes, the signs of overwatered grass can be confused for signs of drought. This leads homeowners to increase watering when really their grass needs less water. When watering your Kentucky Bluegrass, look for the following signs that you are overwatering your grass plants:
- The lawn is spongy or squishy 1 hour after watering.
- Grass blades have begun to turn yellow. Brown is the sign of drought-stricken Bluegrass, while yellow is caused by too much water.
- Orange grass rust, yellow spotted blades, or fungus growing on the lawn.
- Bugs, such as gnats and mosquitos swarming low to the ground. This is often caused by standing water.
If your footsteps make a squishing sound as you walk across the lawn, there’s too much water in the soil. The best lawn care practices for Kentucky Bluegrass are to water infrequently and do not water so much that the lawn floods.
How Do You Keep Kentucky Bluegrass Green?
Water is crucial for keeping Kentucky Bluegrass green. Even more than most cool-season grasses, Kentucky Bluegrass has a low drought tolerance. Extended drought can cause Bluegrass to turn brown and enter dormancy.
- Proper watering practices, with increased water in summer, will keep Bluegrass green.
- Kentucky Bluegrass fertilizing is best done 2–4 times per year throughout the growing season, to promote green grass.
- Consider using an iron-rich fertilizer in a hybrid fertilizer program. Iron promotes green color in Kentucky Bluegrass.
By promoting healthy soil conditions with adequate water and fertilizer, you allow the grass roots to absorb nutrients and moisture, contributing to green coloration. However, Bluegrass will enter dormancy as temperatures plummet towards freezing. The good news is, it stays green much later into the year than warm-season grasses.
Does Kentucky Bluegrass Die in Summer?
Kentucky Bluegrass does not die in the summer, but inadequate water during summer heat may cause it to enter dormancy. This is characterized by grass blades turning brown between June and August.
- Kentucky Bluegrass may turn brown and enter dormancy if it does not receive enough water in summer.
- If Bluegrass receives no water for 4 or more weeks in summer, it may die.
- When watered at appropriate rates, Kentucky Bluegrass will stay green all summer.
When your Bluegrass starts to brown in summer, it’s time to put your sprinkler to use. Increase watering to twice per week, for at least 1 hour per watering session.
Does Kentucky Bluegrass Need a lot of Water?
Kentucky Bluegrass has higher water needs than most grasses. This is due to the fact that it has naturally shallow roots. In high heat, the upper part of the soil dries out the fastest, leaving your Bluegrass high and dry.
In spring and summer, Bluegrass only requires 1–1.5 inches of water per week. This can be delivered by watering once per week. When the temperature rises, Kentucky Bluegrass leaf blades may turn brown as the heat triggers them to enter dormancy. To combat this and keep your grass green, water twice per week. Provide a total of 2–2.5 inches of water per week in the summer. This will encourage a beautiful lawn throughout the growing season.