57January 28, 2009

Last week, I was telling you about the correct way to water your houseplants. Even though the ground is frozen and there is not that a lot of gardening going on outside, I think that it is important to tell you about the correct way to water your plant that will be growing outside come the spring. Yes, spring will come to New England. It always does; even if it is only for an hour on a Thursday in May!

Watering plants outside is not as easy as dumping some water on plants. If you have plants that are growing in containers, the way you water can be determined by how long the plants have been in that planter. Let’s say that you buy a hanging basket full of flowering plants. The plants have been growing in that pot for quite a while. There is also a relatively small amount of soil for all those plants to develop a strong root system. In this situation, the degree of exposure to sun and wind will determine how often you water the plant. If the plant is in a sunny location, you will probably have to water the plant daily during the early part of the growing season. Fast forward to July and the hot weather that comes with July. That same hanging basket has developed longer plants. The plant will need more water to keep the plant alive in the July heat. Now, if you add in some windy days along with that heat and the plants are losing water from the soil and the leaves at an alarming rate. To keep the plant alive, you may have to water multiple times a day to keep the soil moist enough for the roots to supply water to the leaves that are drying out due to strong winds and heat.

If you pot up a container of annual flowers, initially you will need to water the plants daily until the roots develop in the soil. Once the plants start to grow, you may still have water daily, but you may need to add a greater volume of water to keep the soil moist. In July, that same plant may need large volumes of water multiple times per day. Exposure to sun and wind has a great effect on how often you need to water your outdoor plants that are grown in containers.

Let’s take a look at your flower beds and your vegetable garden. The ability of the soil to hold moisture will have major impact on how often you need to water. There are many perennials that you can plant that will require less water. If you want to have a vegetable garden, you will need to water on a regular schedule. After all, vegetables are made up of a large percentage of water. If you have poor quality soil in your vegetable garden, you can add compost or peat moss to the soil to increase the moisture holding capacity.

There is another thing that you can add to the soil in both containers and in the garden to help hold in moisture. The commonly available brand is called Soil Moist. It is a granule that is added to the soil. Once it comes into contact with water, the Soil Moist absorbs the water and expands into a clear gelatin looking substance. As the soil dries, the Soil Moist releases the water back into the soil. Each time you water the soil, the Soil Moist holds onto the excess water and releases it as the plant needs the water. This can cut down on the amount of water that the plants need by 30 to 50%.

Let’s talk about when to water outdoor plants. Most plants take up water better early in the morning. This allows the plant to take up the water it needs before the heat of the day. I have found that you can set up a sprinkler the night before and turn it on when you get up. This is assuming that you don’t get up at 10 AM. By running the sprinkler at 6 or 7 AM, the plants have a chance to take up the water easier. This means you should water your lawn, perennial and annual flower beds and  your vegetable gardens early in the morning.

Watering early in the morning also has another major advantage. If you water in the early morning, the foliage of the plants have all day to dry out. Watering in the evening means wet foliage at night. This can be the major reason that many people get fungus diseases in their gardens. Wet foliage in the relatively cool night time time temperatures will surely start a fungus disease growing. For those of you who have a sprinkler system for your lawn, NEVER let that system come on at 3 Am or earlier. This will cause the lawn to be wet during the night time. Again, a perfect breeding ground for lawn fungus diseases. Better to have the sprinkler come on at 5 or 6AM. Once the watering is done, the grass will dry out in the morning sun.

Well, hopefully this clears up some of the problems that may crop up when you are watering outdoors.
I’ll talk to you again next week.