So after a wet and cool spring, the dog days of summer have arrived. Long gone are the benefits of the early season rains as we settle in to dusty, dry, and cracked earth to anchor our struggling plants. But do not fear – maintaining your summer landscaping is easier than you think.
It is really important to water deeply and early in the day. Watering late in the day, during the hottest time of day, is not the best time. Most of the water will evaporate rather than reach plant root systems. Conversely, watering at night, before sun-down, promotes a beneficial environment for disease to grow on your struggling plants. If at all possible, water early in the morning when the ground is able to absorb moisture.
As far as how much to water, plants have varying requirements and soil conditions can vary greatly in one landscape space. The general rule of thumb, and again, it’s a rule of thumb, is 1” of moisture every 5-7 days. This can be measured by leaving a tuna can or dish in the garden and watering thoroughly until the container is full. Now this is for landscape beds. For trees, it’s best to leave a hose at the base at a slow trickle for 20-30 minutes depending on the size of the tree and soil condition. Again, this is suggested, not a finite answer. If in doubt, water your landscape and then dig a hole at least 6-8” deep and check the moisture in the soil. You should be able to make a doughy ball with the soil, not be able to squeeze excess water from it.
Believe it or not, more plants are lost to overwatering than underwatering in the summer months. Unfortunately, the symptoms for overwatering and underwatering are very similar – often yellowing leaves. If you have an in-ground irrigation system, continue to check your property and monitor water flow. If you have soaker or drip irrigation, check it frequently. The holes can get clogged, and the hoses can be disturbed by root growth, dug up or even chewed by animals. It’s important to check the integrity and accuracy of your irrigation system.
Remember also, plants such as river birch and sycamore will shed in hot and dry conditions as a means of protecting themselves and preserving their resources.
For your lawn, more frequent watering for shorter amounts of time is best. Remember those roots are closer to the surface than shrub, tree, and perennial roots. It’s also best for lawns to mow high in the summer months so that the grass is not being stressed. As far as fertilization goes, there are many schools of thought on this, but the general consensus is it’s best not to fertilize plants when they are under stress, and this includes grass. It’s best to not fertilize at least a month prior to when hot summer temperatures are expected. Just keep watering, and not before nightfall. Keep those mowing blades sharpened and clean periodically with rubbing alcohol to prevent spreading disease.
Don’t give up! Some of your plants will go dormant in the summer heat. Give them a chance, and do not yank them from the yard, as many will revive in the fall with cooler temperatures. If in doubt about the health of a plant, The Prince William County Extension Service is an amazing resource and hosts plant clinics at local farmers markets or sometimes garden centers. You can contact them directly at 703-792-6289.