Watering Plants in Summer
It is HOT. Thirsty hot. We can all use a little extra hydration when it’s hot, and so do most of our plants. Do you know if you are watering well? At the right time? Are they getting enough, often enough? Too often?
The “1 inch” of water guideline confuses some of us because we have different containers to water with, so I just use my finger. To test the soil with your finger, poke down a few inches near the stem to check the root zone, because that is where the water take-up happens. A soil moisture meter works well too. Even if the surface appears to be a bit dry, there may still be moisture down at the roots. If there isn’t, then get the watering can or the garden hose. Remember – it’s enough when the water reaches down enough to get to the roots. On some of our larger plants, that may take a while, because slow and steady wins the race here. Too much volume at once and the water runs off the top and goes elsewhere – not where we need it to go.
Watering in the morning is best in order to avoid evaporation from the heat and dry wind of the afternoon. Also, watering in the morning allows the leaves time to dry out if they get wet and buffers the stress of the heat throughout the day. Water droplets also act like mini-magnifying glasses under the afternoon’s full sun glare, causing the cells under the droplet to get scorched, so morning watering works better for us and our plants.
Water the roots, not the leaves. Applying the water to the base of the plant either with a drip system on a timer for us absent-minded gardeners, or with a long-handled water wand helps keep the leaves, veggies, and fruits dry. That helps prevent the diseases that thrive in moist areas. Our fruits and vegetables are largely water, so consistent watering helps the flesh and outer “skin” develop at an even rate, producing better quality produce. Too little or too much will show up in your garden tomatoes with either blossom end rot or cracked skins.
Remember that containers can’t take advantage of the capillary action of liquid in the ground – the pots are limited and tend to dry out faster than soil with high organic materials. The container color also matters. Just like the dashboard of a car gets hot, dark containers absorb heat, and the roots of the plants struggle with the added heat. Lighter colored containers reflect more heat. Standard clay pots are porous, so water evaporation happens faster than with plastic pots. You’ll want to choose containers carefully and keep an eye on how your plant is holding up.
=PMP is key. PMP means the Permanent Wilting Point. It is when there is no water available to the plant. It depends on the plant variety and varies with soil texture and pore space size. The soil still contains some water, but it is difficult for the roots to extract it from the soil. Using mulch in every planting situation helps retain moisture, especially if it is natural materials. Dark, reflective plastic mulches tend to do the same as dark containers.
Don’t forget the kiddos! Get everyone outside into the garden – watering plants, and having super soaker contests and running through the sprinklers are some of the best go-to summertime activities for kids.
Minda Daughtry is the Horticulture Agent for North Carolina Cooperative Extension in Lee County.