by Mark Levisay
It is one of gardening’s great contradictions that the symptoms of under and over-watering look similar (drooping plants, browning leaves), so it’s important to pay attention to the water needs of the plants in your garden.
How much water
A rain gauge is a good place to start, as we’re blessed by year round rains in central VA, and many weeks nature will give our plants plenty of moisture. In general 1” of rain per week will satisfy most mature plants, but there are certain times when a single rain storm may not be adequate. This is especially true of starting seeds or transplanting seedlings, as they need frequent, shallow watering to get them going. Plants also need steady moisture levels when they’re setting fruit or seeds (melons, beans) or during head development (broccoli, cabbage). Asparagus needs good moisture early on as they are developing spears at this time of year and we’re harvesting them and expecting more to grow!
Containers are probably going to need more than 1” of water per week, especially in the hottest summer weather when they may need water every day. Lawns generally only need water when you’ve planted seed. Most of our lawn grasses are “cool season” meaning they perform best in spring and fall. They’re experts at becoming dormant in the heat of the summer, which may not be attractive but does them no harm. The grass will green up when the sun is lower and more rain occurs.
A watering wand allows you to deliver water to the base of the plant.
How to water
There are several methods of delivering water to plants. If you have a few containers, use a watering can to deliver water to each plant directly. If you’re using a hose, I recommend using a watering “wand” several feet long with a shower type head to be able to easily reach the base of the plant. In general you want to avoid getting water on the plant leaves, especially if you are watering in the evening. Wet foliage can encourage fungal diseases to grow and spread-this can be a major problem in your tomato patch. Oscillating and impact sprinklers are good at covering large areas, but need to be used early in the day, as they’re going to get a lot of water on the foliage. If you use this method during the heat of the day you’ll also be fighting evaporation, and waste a lot of water. I’d use these sprinklers when I was planting new grass seed in my lawn.
Soaker hoses
I personally use soaker hoses extensively in my vegetable garden. They are not really useful for seed germination, but once plants get roots established they provide deep water without wetting the leaves, and minimize evaporation. I set up “circuits” so that a single run of hose will water all of my tomatoes and another will do the pepper plants. This way you can easily deal with different plants’ varying water needs throughout the growing season.
Soaker hose laid down in the beds before planting tomatoes.
Most soaker hoses come with a pressure reducing washer at the hose connection end. This is important, as the normal water pressure coming from the house will cause weak spots in the hose to spurt out too much water and leave other spots dry. The small hole in the washer reduces the pressure and allows for a slow gentle soaking from the hose. I also use a simple wind-up timer on the spigot at the house to control the length of the watering session. You want to get a good deep watering but not flood the bed. It’s really easy to forget you’ve got the soaker hoses going, so I usually set the timer for about ½ hour per circuit. It can be easy to over water with the soaker hoses, so poke down into the soil if it looks dry at the surface to see if you still have moisture down deeper.
Pay attention to weekly rainfall, water properly and only when needed. Your plants should be happy all through the summer!
Have a garden question? Send me an email at marklevisay@gmail.com.