The 2 Minute Gardener

Wednesday, April 11, 2012

Gardening Tip - Fixing Poor Soils with Gro-Power

As mentioned in the 2 previous posts, hard clay soils present a series of challenges for growing healthy plants. Gypsum is the best additive for removing salts from a clay soil. Today’s post will talk about Gro-Power.

Gro-Power is a soil conditioner that adds organic material and mico-organisms back into the soil. Without these micro-organisms, the soil cannot process any plant food for the roots of your plants. Basically, trying to feed plants stuck in hard clay soil is like trying to eat pizza with your mouth wired shut. The food just has nowhere to go. With an organic fertilizer like Gro-Power, the plant roots can actively process the nutrients in the soil.

Gro-Power can be used in both new and existing landscapes. For new landscapes, rototill Gro-Power in at the rate of 150 lbs for every 1,000 sq ft. For existing landscapes, use 1 to 5 cups based on plant size every 6 months (see product package for details).

Using gypsum and Gro-Power will help turn that rock hard clay soil into a better environment for your garden. Gro-Power is available at most nurseries and garden centers.

Tuesday, April 10, 2012

Photo - Garden Gypsum

This is available at Miramar Wholesale Nursery

and other good nurseries.

Photo by Doug Kalal

Gardening Tip - How to Fix Clay Soils with Gypsum

In the previous post I talked about identifying clay soils, now its time to fix the problem. Clay soils have 2 basic problems that are harmful for healthy plant development. The first is that the chemical makeup of clay soil tends to be high in salt and the salt is tightly bound to the soil particles. This chemical composition also holds water tightly to the salt and soil, so that drainage is poor. The second problem is that clay soils tend to be lacking in organic material and the soil micro-organisms that help plants to thrive. Some California natives actually prefer this type of lean soil – but I will save that for another post.

To address the first problem you need to add some gypsum to the soil. Gypsum is another word for calcium sulfate, a chemical that replaces the sodium in the soil with calcium. This chemical action helps to unlock the soil, getting all that salt to flush away from the root zone, which in turn lets the water drain away as well.

You can either use gypsum for a new landscape by mixing it into the soil with a rototiller, or by spreading it on an existing landscape and watering it in. The standard gypsum powder takes awhile to take effect in the soil, so you can also use a liquid form of gypsum to speed up the process. There are various types and strengths of gypsum on the market, so always follow the label when it comes to how much to use. Gypsum is not a fertilizer, so you will still have to feed the plants but it will allow the soil to better process future plant food. Gypsum should only be used on clay soils; it is worthless for sandy soils.

Since we have gone over the 2 minute mark, part 2 will have to wait until next time when I talk about Gro-Power.

Monday, April 9, 2012

Photo - Good Soil vs. Clay Soil

Here is sample of clay soil. Notice the gray, chunky texture of the soil.

The molecules that make up clay soil are more tighly bound

together, which means the soils hold onto water more tightly than good soil.

Here is a sample of good potting soil. It is darker and has

a finer texture than clay soil. Water can drain better through

this kind of soil.

Photos by Doug Kalal

Gardening Tip - Identifying Clay Soil

San Diego is a gardener’s dream. Our moderate temperatures mean that we can grow a dazzling array of plants all year. The downside to San Diego is that in many parts of the county we have poor native soil for growing all those beauties we see in Sunset magazine. There are several types of soil in the county. Today’s post will cover heavy clay soil.

How do you know if you have this type of soil? First dig a small shallow hole about 12 inches wide by 6 inches deep. Is the soil hard to dig, even though you are not hitting any rocks? Next fill it with water and let the water drain out of the hole into the soil. Does the water drain quickly while you are standing there or does it just sit there like a really gross bird bath? A really gross bird bath means you have clay soil. Still not sure? Let the water drain completely out and then refill the hole with more water. If the second batch of water drains slower than 1 inch per hour, you have clay soil.

Another test is to scope out a handful of soil from that wet hole. Does the soil feel like playdoh in your hand when you squeeze it or does it slip through your fingers in loose pieces? Wet clay soil will feel like wet clay (thus the name). Because of its dense structure, clay soil really holds onto the water which can drown a lot of great plants that need good drainage to survive. So what can you do to fix this? Tune in tomorrow when I will tell you how.