While you may water your newly planted tree very well for a few days, we all suffer from the reality that we never have enough time to do the things we want to do, and a week later, we have forgotten to water the newly planted tree. If in the first few months of being planted the soil around the new tree goes dry, the plant will experience serious and potentially harmful stress.
One solution to this problem is to add a kind of watering safety net to the hole, before you plant your tree. Water absorbing polymers look like sugar when dry, but when exposed to water, they absorb that water and effectively become sponges in the soil holding water aside for those times when the soil begins to dry out. For details on how these polymers work go to Understanding Polymers
Polymer Gels are only effective when thoroughly mixed into the soil in the hole before you plant your new Tree. Sprinkling the crystals on top of the soil surface after you have filled the hole with the plant and soil does not work. Polymer Gels can be mixed with the soil in the planting hole in either dry or wet (hydrated) form. Although the crystals become somewhat gooey and gloppy when hydrated, it is easier to determine the proper proportions of gel to soil when they are in this state. To hydrate the crystals, start off with a teaspoonful in a cup of water (or a tablespoon in a pint). Let it sit for an hour or two, then observe how much of your particular brand of crystal it takes to fill the container with fully hydrated, jelly-like material. It takes anywhere from 30 minutes to several hours for the material to absorb all the water it can hold. Now you are ready to mix the gel with soil.
In most cases, you can add about one tablespoon of dry polymer crystals or about a pint of the hydrated gel to serve the needs of the newly planted Tree during its first year of growth. Put half in the soil in the hole and the other half mix with the soil going to fill the hole after the plant is in place. Exceeding the recommended amounts may result in your plants being pushed right out of the soil as the overabundance of gel crystals absorb water and swell.
How Much to Water If You Use Polymers
Polymer Gels take a week or two to become fully activated. During this time it is important to water as if no crystals were added to the planting hole. The new Tree’s roots need time to begin to grow into contact with the gel crystals so they can extract the available water. After a week or so the gels should be activated. It may still be difficult to determine whether it is okay to reduce the frequency of watering, because the surface soil may be dry to the touch even though the gel crystals deep within still contain plenty of water. Unfortunately, water meters sold for houseplants do not work with soil that contains Polymer Gels.
A good guideline is to water Polymer Gel treated soil around a newly planted Tree about one third to one half as often as you would water the untreated soil. For example, if you watered your new transplant every other day that it did not rain, then with the crystals you can go three or even four days before watering again, assuming it does not rain. If your soil drains pretty well, it is difficult to over water your new Tree, but if you have a drainage problem, you need to be careful not to add more water than the plant actually needs.
After the first year, your Tree has established itself in its new site and while the polymers are still there, they are not a major factor because the roots have grown out past the area with the crystals.
For information about buying Water Absorbing Polymers click here to go to the Yardener’s Tool Shed.