Watering Your Plants

Posted: August 20, 2014

Believe it or not, there is a lot to know about watering your garden! You say you just turn on the sprinklers, or stand with the hose in the evening and sprinkle your gardens? Sorry. Wrong on both counts!
Coreopsis verticillata 'Zagreb' is a long blooming native perennial that will grow nicely all season without having to be watered.

Coreopsis verticillata 'Zagreb' is a long blooming native perennial that will grow nicely all season without having to be watered.

Overhead sprinkling is an inefficient and wasteful way to water.

Much of the water is lost through evaporation before it ever reaches the soil, and wet foliage encourages disease.   Watering in the evening is especially detrimental because the leaves stay wet longer than they would in the morning.  The longer the leaves stay wet, the more problems you are inviting.

Select the right plants.

If you are careful about plant selection, you can get away with rarely watering ornamental plants once they are established. 

Healthy soil is the key.

The health of a plant often comes down to the quality of your soil and the size of the soil pores which are vital for holding both air and water.  Clay soil tends to hold water, and in some cases, the soil will not drain properly.  The pores are too small to hold air, and too close together to allow water to pass through, often resulting in root rot.  Sandy soil has large pores, which allow the water to drain through the soil very quickly.  Both conditions make it difficult for most plants to thrive.  Like Goldilocks, we need to find the soil that is just right!  The solution is the addition of organic matter.  It will help the sandy soil to hold water longer, and it will improve the drainage abilities of the clay while keeping it friable (workable, not rock hard).

Where do you get this "organic material"?  Compost, leaf mold (rotted leaves), aged manure, or mushroom soil are excellent options.  I bought a load of mushroom soil to help create my first gardens.  Now I add compost regularly, and also a mixture of mulched leaves and grass in the fall.

Use mulch to conserve water and help with weed control.

Anything that shades the ground, including ground covers will help conserve water.  Just be sure the mulch is not too deep as to actually block the water from reaching the soil.  Two or three inches of mulch is sufficient.

Don't work soil when it is wet.

Knowing the importance of the correct size of your soil's pores makes it easy to understand why you shouldn't walk on or work in soil that is wet.  You will be squashing those pores making it very difficult for them to hold the air and water your plants need.

There are many options to choose.

Whatever system you choose for applying water to your plants, remember that the water should be added at the root level, never on the leaves.  A vegetable garden is going to require more consistent watering than a perennial garden simply because your vegetables, percentage-wise, are mostly water.  However, all the good gardening principles concerning soil remain the same.  

A soaker hose which allows the water to ooze through it, works well.  You can snake it through your garden, then cover it with mulch.  I prefer a hose-end watering wand designed to reach high, hanging plants.  I use it to apply the water at ground level without having to bend down.  (I guess it helps that I am short!).   Hand watering gives me the chance to personally interact with my plants, checking for insect damage, disease, and weeds.

Beware of shallow watering.

Shallow watering encourages shallow roots that won't hold up to stress.  Many people simply sprinkle the soil surface, and feel they have done the plant a favor.  It's important, whether the water has come from rain or from your hose, to check how deep it has penetrated into the soil.  Most plant roots, or at least their feeder roots, are in the top six inches of your soil, so when you finish watering, dig down to see if the dampness extends six inches or more.  You may be very surprised to find how dry the soil still is.

In Pennsylvania, an average recommendation is an inch of water a week for an ornamental garden.  It's easy to check and record rainfall with the help of an inexpensive rain gauge.  Remember, a vegetable garden needs considerably more water than an ornamental garden, and newly planted shrubs need consistent attention for the first year.