Gardeners only pls! What do I need to mix with CLAY soil to make it a good soil for perennials?

Question

I've been trying to plant on clay soil but my plants always die and basically won't survive no matter how much fertilizer I put. I know there is something that I need to mix with clay soil to make it a healthy soil. I tried compost and those expensive gardening soil but it seem like it's not enough. I've already spent a lot of money on plants because they keep dying on me. What am I suppose to do? I need help? Thanks. Ann

Answer 1

Use gypsum, you dig it into the soil and it permanently creates break up in the soil to allow air and water penetration, allowing the plants to grow. You only need to do this 3 times. I use this in my garden and other gardens and it makes a real difference. Always add compost and organic matter as well this will also improve the soil over time. I'm a qualified Horticulturist and Gypsum is the first thing they teach you about to break up clay, yet when I list it as an answer on this site people ignore my answer. Farmers use it by the truck load in my area and it doesn't change the PH of the soil. If your doubtful just do a small area as a trial and see how you go. Good luck clay soil can be very frustrating.

Also try and pick plants that like a clay soil. Try some of the English gardening sites eg BBC Gardening. England has some terrible clay sites and many of their plants, available around the world are adapted, and suitable.

Answer 2

When you deal with a garden you deal with the soil first then the plants. You thankfully recognized it was not you but your soil that causes you you problems. Now what to do?
Ann, you are going to get suggestions from manure to sand and all of those are wrong. They improve the composition of the clay, however, they can not, nor will not, correct any soil. Clay is not a soil in a sense. It is merely a character of soil. Would you consider sand a soil or a part of a beach? Both can and do substain plants but in different ways.
Clay soil has a certain PH level. You can till it and put in additives until it reaches the PH level that supports any/all plants. The monies you spend trying to get the soil to what you want is lost. Lost in the time spending the time enjoying the plantings you have.
The first thing you have to do is truly roto-till your soil. A local store should provide you with a roto-tiller of 12" for less than $30. a day. Buy a bag of Sphagnum Moss ($3.50) and a bag of Gypsum ($3.00). Roto-till, as best you can the existing bed.
I'll assume you want a small bed. Start small then enlarge.



The above will give you a bed of roughly 10x20. It is tough work to roto-till a clay bed. It is impossible to do it by hand unless you have hours and hours to do so. Work the Moss into the bed with the tiller set at it's lowest setting. Let the bed rest for at least a week.
Initally some flowers do not care about their soil. The efforts you made via the roto-till and moss will draw the roots to the moisture and hopefully make them healthy. The Gypsum you apply liberally and without hesitation. It counteracts the soil contraction of clay. It is in fact the only non chemical agent to do so. First you have to break the soil bond formed by the clay.
I grew gardens of roses and annuals in center city Phila., Pa. I design them now for housing developers and the like. Clay is nothing more than an problem. More important is what you want to grow and the sun/water it can get. You can contact me at [e-mail]

Answer 3

Mulch is needed to keep the soil moist. You can add the (bark type mulch at the bottom of the planting hole and then again on top to hold in moisture.

We have clay too. It's impossible to grown anything without amending the soil. If you are adding too much fertilizer, you could be killing the plant. Compost is the right ingredient but you dont need fertilizer except one or two times a year. The compost will act as a fertilizer.

Another thing. If you are overwatering, clay retains moisture and it could be killing the plants. Water in moderation.

Good luck fellow clay soil person.

Answer 4

Lots of good answers here. I've been growing vegetables successfully in clay soil that should be used for building material instead of being planted in. Here's what I have done to get a rich, friable soil over the last 35 years:
1) When I first attacked the patch that I wanted for a garden, I turned the soil - weeds, grass, and all - with a shovel, then rototilled it, then took all the leaves and grass clippings from my neighbors and covered the area with that, and then rototilled it in again. Then I raked in a layer of chicken manure, let it get rained on for several months, then planted. Around the plants, I mulched with grass clippings and fertilized with fish emulsion. First year results: stunning tomotoes, excellent corn, fantastic cucumbers, lettuce, beans, and squash - terrible carrots, radishes, onions and beets.
2) Year 2 and every year thereafter, just rototilled as much organic material into the garden as possible - sometimes up to four inches - then covered it with as much additional mulch as available, but no more than two inches thick. Let that winter over, then plant through the mulch. I've only used organic fertilizers and organic pesticides. Results: excellent vegies of all types, with only a few pests now and then.

I've never used sand because I think it's a waste of time. Clay is lighter than sand, so the sand sinks and separates from the clay anyway. It doesn't have much effect on the top four or five inches of the soil if sand is the only amendment. You have to combine sand with organic material, and even then, it will sink during heavy rains and watering.

Here's another idea. After heavy rains, go around and collect all the earthworms that you can find slithering about on concrete or asphalt trying to get a breath of air. Toss them into your organic rich garden or compost pile (not new material - too hot for them). They will help break up the heavy clay soil and fertilize it with their droppings.

One final idea. Overseed the soil in winter with clover or winter rye grass. Rototill it all in after the rains have stopped and the soil has dried out a bit. This is a bit messy, but it really enriches the soil.

Answer 5

You need to add several things, It certainly may have seemed like you added alot of compost, but it probably wasn't enough. So #1 Compost, #2 Coarse Sand, #3 Gypsum. Roto-till all this together. I don't know how big an area you are working so I can't give you the amounts If you think it was a lot of compost add more. Buy the least expensive compost you can get you are after volume at this point. You should add compost and gypsum yearly for several years, and even good soil will benefit from the addition of compost. I would not add more fertilizer right now you may have over fertilized and could contribute to your problem.

Answer 6

Ugh, clay soil. I have the same problem, and I HATE it. Grrrrrrrrrr.....

Well, there is the LONG way and the QUICK way of fixing this.

The quick way is to do soil replacement. Basically you mix up yer own potting soil, and replace. It will cost you some, but the benefits are pretty good.

The long way can take you a year or even longer to fully ammend. Till the area, either with a rototiller, or by hand, apply plenty of mulch, and blood meal, sea weed or fish emulsion (all are 100% natural fertilizers). I stay away from any and all synthetic ones.

But till up the area to about 8" to 1 foot, apply the fertilizer, some perlite and even some peat moss, and if you want some steer or chicken manure.

Answer 7

Have you tried mixing in some sand, peat moss, and/or a product that is called "Clay Buster"? Here in Michigan, we have a lot of clay in the Detroit suburbs. Every spring I buy several bags of this additive for clay. What it is is the same stuff sold for planting aquatic plants in a pond. It's little, tiny baked-clay granules. You work it into the clay as well as you can. I like to also add compost. You could dig all the clay out of a small flower bed (down to about 6-8") and replace it with good-quality planting soil but the clay actually has a lot of built-in nutrients. If you just dig out the hole where the individual plant will sit, you are creating a "soup bowl" effect--not good if you water a lot or it rains a lot. The plant will end up sitting in too much water and die.
Plants Recommended for Growing in Clay Soil
(Zones will vary with variety)
Amsonia Blue Star (Zones 5-9)
Asclepias tuberosa Butterfly Weed (Zones 4-9)
Aster (various) Aster (Zones 4-8)
Coreopsis Tickseed (Zones 4-8)
Echinacea purpurea Coneflower (Zones 3-9)
Eryngium yuccifolium Sea Holly (Zones 5-10)
Helianthus angustifolius Swamp Sunflower (Zones 6-9)
Helianthus x laetiflorus False Sunflower (Zones 5-9)
Heliopsis helianthoides Ox Eye (Zones 4-9)
Hemerocallis Daylily (Zones 3-10)
Liatris pycnostachya Kansas Gayfeather (Zones 4-9)
Liatris spicata Blazing Star, Gayfeather (Zones 4-9)
Monarda fistulosa Wild Bee Balm (Zones 3-9)
Ratibida pinnata Drooping Coneflower (Zones 3-10)
Rudbeckia hirta Black-eyed Susan, Gloriosa Daisy (Zones 3-7)
Sedum 'Autumn Joy' (Zones 3-10)
Silphium integrifolium Prairie Dock (Zones 4-7)
Silphium laciniatum Compass Plant (Zones 5-9)
Silphium perfoliatum Cup Plant (Zones 5-9)
Solidago Goldenrod (zones 5-9)
Vernonia noveboracensis Ironweed (Zones 5-9)
Yucca filamentosa Adam's Needle (Zones 5-10)
Ornamental Grasses Suited for Clay Soils
Acorus gramiineus Grassy-leaved Sweet Flag (Zones 10-11)
Andropogon gerardi Big Bluestem (Zones 2-7)
Elymus canadensis Canadian Wild Rye (Zones 3-8)
Miscanthus sinensis Eulalia Grass (Zones 4-9)
Panicum virgatum Switch Grass (Zones 5-9)
Pennisetum (various) Fountain Grass (Zones 6-9)
Sorghastrum nutans Indian Grass, Wood Grass (Zones 5-8)
Spartina pectinata Prairie Cord Grass (Zones 4-7)

Answer 8

Do not add any more fertilizer for a while, but add sand, lots of sand until it feels right, light and easy to plant in. Add peat, or start a compost pile that will include clippings, lime and SAND, then in a season start from the bottom of the compost pile adding the oldest stuff first for the rest of your gardens life, a little bit every year. A garden is always a work in process, like raising children.

Answer 9

I would try doing some research on native plants in your area. If there are plants that can grow in the wild in the clay in your area, then surely you can grow these plants too. If you're putting time and energy into researching soil ammendments, then why not do the same for plant selection.

I have clay soil and have no problems with the native plants that I have planted.

Answer 10

I have the same problem at my house. I live in Oklahoma were clay soil is practicaly everywhere. I keep my plants alive by digging out the hole where I'm going to plant the flowers and I exchange the clay soil for miracle grow soil that you can buy at walmart. It's only $3 for a large bag. I don't recommend mixing your clay soil with anything. Your plants won't grow in the clay because it keeps drying your plants out and doesn't have enough nutrients.