I guess I can call this my first garden blog of the 2016 season. And, I HAVE CLAY. And lots of it. I'm not alone as nearly 60% of Clark County, Washington has the same orange, slippery, kind of clay that Pueblo Indians would have traveled miles to obtain. Although this kind of clay is great for making pottery, it is not what you would call "plant-friendly". As a matter of fact, clay is probably the leading cause of plant decline in the area which we live.
|Rhododendron dying with root rot|
yourself. You paid $39.99 for this ugly, half alive shrub. The problem is probably CLAY.
I hear it all the time. You thought you took every precaution. You even put in the potting soil. But here is the problem. Potting Soil is exactly what it says it is. It is a formulation made for POTS & CONTAINER GARDENING. What has essentially happened is this. Remember the big hole you dug to plant your shrub in? Congratulations, if you have clay, you have just dug a swimming pool for your plants roots to swim in. As we all know, roots don't really take to swimming. Just like us, they need air. The potting soil you added is not an amendment designed to break up clay.
In the land of CLAY, you must first amend your clay soil and then plant your landscape plants. There are several products on the market available claiming to break up clay soil. Many of them are effective. However, it's not really necessary to go out and buy these products. If you keep a compost pile, this is the first place to start. Adding organic matter to your clay soil is the first step to turning your clay back into good dirt. If you don't have access to good compost (ie. decomposed leaves, lawn clippings, etc), a good product to try is Gardener & Bloome Soil Building Compost. It is available at most garden centers and is sold in three cu. ft. bales. The bag goes A LONG WAY so chances are if you are amending a small planting area, you will only need one bag.
I always recommend that for the amount of clay you are amending, you add an equal amount of amendment. So you essentially end up with a 50/50 mix. It has always seemed to work for me. Also, if you really want to get stuff growing, add some organic amendments like jersey green sand, feather meal, bone meal, alfalfa meal, rock phosphate, etc. These amendments are absent in your clay and will help later in nourishing your garden. They will provide valuable building blocks for your soil to take in water, nutrients, and they wont harm the mycorrhizae which thrive in healthy soil.
Many of my customers come to me each year with the same question. Can I just add some sand to my clay soil? I tell them all the same thing. Sure, you can add some sand but it isn't really going to solve your problem. The only thing that will truly improve your soil is organic matter. Amendment will definitely improve your drainage and soil consistency. So I recommend both. If you are in a spot where you can neither obtain organic matter or add amendment, the solution would be to elevate your plantings above grade so that they are never sitting in said swimming pool.
Above grade planting has some advantages that you may have never thought of. First, it adds a degree of dimension to a yard that is flat. Second, it improves drainage to the roots of your plant because it is not sitting below grade. Third, and my favorite, you don't have to dig as big of a hole for your root ball to fit into. My back is feeling better already. Creating berms and 'raised beds' can change the whole look of your landscape for the better.