New installations should always be watered immediately after planting. Keeping newly planted and young plants well-watered is essential as their root system has yet to develop fully. Check the soil around the base of the plants, as this soil may dry out faster than soil between plants. Too much water can encourage disease and cause plant death, so it’s important to pay attention to the climate and the location of the plants to determine when and how much to water. Always check soil moisture before watering by sticking your finger in the soil up to the second knuckle.
Early morning is the ideal time of day to water your garden. This allows you to soak the roots and lose little water to evaporation. Also, foliage dries quickly as the sun and temperatures rise, making plants less prone to fungal diseases that settle in on wet leaves.
Newly Planted Perennials:
Week 1: Check newly planted perennials every day. Water only if needed.
Weeks 2-6: Water 2-3 times per week, depending on environmental conditions.
Weeks 6+: Water as required, more in summer and less in fall.
Perennials that are said to tolerate drought are drought tolerant only after they have become established.
Established Plants:
Established perennial beds (beds that have existed for more than 2 years) should get an average of 1” of water a week. Avoid watering established plants every day. A quick drink every day just encourages spindly roots. Instead, deep and less frequent watering is best to promote long roots. They’ll grow down into the ground so they stay cooler and absorb moisture and nutrients that are held there. Perennials with an established root system can also handle a little drought stress.
Noticing wilted plants is usually a good indicator that it’s time to water. However, droopy leaves and stems aren’t necessarily a signal that the plant is drought-stressed. Many perennials wilt in the afternoon, especially on hot, sunny days, but they’re fine by morning.