Garden Planning

What To Do With Clay Soil

I recently had a reader ask what to do with clay soil in her garden and I promised I would write about it for her and the rest of the gardeners in Indiana.

You might wonder if you have clay soil or not and I can just about guarantee you that you do unless you were lucky enough to have purchased a home where the previous owner amended the soil for you. I’ve had several homes in this wonderful State and every one of them had heavy clay soil. Trust me, when you want pretty flowers and luscious vegetables they are not going to work well in clay soil.

How do I know if my soil has clay content?

You could have it tested but you can determine it for yourself, too. Dig a hole. If you can take that soil and form a ball with it…it has clay. Another hint would be when you dig or till the soil sticks to your shoes or boots and your spade or shovel. Although clay is wonderful for pots to be made from it is not so great for most plants to grow in. Why is that? The clay content in soil is dense and hard for the small roots of most plants to grow through. It also hold moisture really well and that is not always such a good thing. It can cause some plants to actually rot from too much moisture.

Breaking Down The Clay

So, what do you do? Can anything be done? Yes, it is going to take some work but you can get your soil in a condition to grow things and in the very first season, too. Let me just say something first, if you have read or been given advice on treating one hole at a time; do not take that advice. In essence what you do with that method is you create an outdoor clay pot. If you only treat the soil where you are growing one plant the plant will do nicely for a while. The surrounding clay will cause it to eventually start to curl around in the good soil because it can not penetrate the clay. You virtually get the same thing as a potted plant that become root bound. So, just don’t do it.

Instead do an entire area at once. You can dig it by hand or use a tiller. Personally, although back braking, I like the good old fashioned shovel in hand method. For really large areas the tiller works but I don’t think as well as concentrating on an area with the shovel. You get a better mixture with less big clumps of clay to work with.

If you are going to be working in an existing bed, you will need to remove the plants that you want to keep before you start working the soil. Don’t worry, you will get to re-plant them when you are done. You are going to want to add about 6 to 8 inches of organic matter to your area. Break up the clay soil with your shovel and then add the organic matter. It can be just about anything you can find. Grass clippings (not treated with any chemicals), compost, or shredded leaves work very well. You will want to spread the organic matter over the soil and then start to work it in so that you have about 6 to 12 inches of the mixture of old clay soil with the new material you have spread around. The area will be a little taller than when you started but it will settle over time.

I like to work the soil, wet it and let it sit for a day or two. Then I go out and mix it up one more time. After that, my old and new plants can be planted. I also add another mixture a couple of times throughout the growing season; about mid-way and towards the end of the season. After a couple of years of doing this, the clay won’t be much of a problem anymore.

Clay soil that has not been helped along has a tendency to be on the alkaline side so adding some acid to the soil will also be beneficial in most cases. Unless I have true acid loving plants to treat the soil with, I typically apply the acidic food at half the strength. It is hard work in the beginning but you will never regret putting in the effort because your flowers and vegetables will grow better and produce more.

What To Do In March

Most of the time in the month of March we will have some days that are warm enough that we can begin to work a little in our gardens. It has not been that way this March to work on our “to do list” but there have been a few days that we could go out and play in the dirt.

March is a great time to do some clean up in the beds whether they are our flower beds or the vegetable beds. Start to rake out those dead leaves that fell last fall and generally clean up the area. It is also a great time to be making final plans for just what new things you will plant and where they will go.

As I write this to do list for March it is snowing and is just too darn cold to be out there working the soil. If it were warmer, I could in theory be planting some new perennials but they would need to be the hardiest ones available. Although the guys over at GardenEaze will tell us that we can begin to plant the seedlings that we grew indoors over the winter, I don’t necessarily agree with them. The premise is that if there is a chance of frost we must go out and cover them so that they don’t get their little feet burned with the evils of Mr. Frost. I’m sorry, that is a lot of work and it has been my experience that those plants that I have tried to put out in March just never do well, if they survive at all.

Even though the calendar tells us that it is officially Spring, here in my neck of the woods it is still cold and will be for a while. Oh sure, we actually had some days that got up to around 60 degrees but our weather is not going to sustain those kind of temps on a regular basis.

It is a good month to add some fertilizer to our old beds. You want a pound of nitrogen per 1,000 square feet of garden area. That would work out to be around 1 pound of 10-10-10 fertilizer to a 10 square foot area (10 feet by 10 feet). Have any 1 pound coffee cans sitting around with nothing to do? Take one of those to help you measure. The can will hold 2 pounds of fertilizer.

March is a good time to get out there and cut back the plants from last fall. You know those sorry dead looking stalks that we didn’t get to before the snow started to fall. Cut them back now before they start to grow again. Not only will the area look better but the plants won’t be trying to “heal” the dead stuff and will use their energy to help the new shoots to grow.

Books will also tell you that this is the month to pull back the mulch that you put down to protect the plants over the winter. You can do that, but a word of caution. Don’t take it too far away, you will probably need to put it back if the weather turns nasty. If you have lived in Indiana for any length of time at all, you know it will still get nasty with cold for another month or so. Personally, I leave the mulch right where it is until the chances of frost are just about gone.

From my own experience in gardening here in the great state of Indiana, March is still a planning month for the most part. It is an exercise in patience for me because I want so badly to get out there and get my hands dirty but I hold myself back. I’ll do clean up but I do not set any plants out yet. I’ll fertilize but that is about the extent of my gardening in March.

February Jobs For Indiana Gardeners

You might not think that there is much to do in the cold month of February in your Indiana gardens. Well, that is only partially true. Obviously it is too cold to be out in the actual garden beds but there is plenty that can be done inside to prepare for planting once the weather warms up. Now is the optimum time to be sowing seeds indoors for many plants both floral and vegetable. So, let’s look at the jobs that a gardener can work on during February.


Get your potting soil ready and collect as many containers as you can from around the house and start sowing those seeds so that you will have plants that will transplant nicely when the time is right. About the first of February you should be planting seeds for:

  • gerbas
  • petunias
  • impatiens
  • wax begonias

Around the middle of February it is time to sow seeds for:

  • ageratum
  • lobelia
  • love-in-a-mist (Nigella)


You can start some of your vegetable plants this month as well. I suggest that you get a few Seed Starter trays to work with. I like the ones that have several small little indentations that I can keep like seeds together. The biggest thing to remember for sowing seeds indoors during the winter is to provide enough light for the seeds to germinate. You plants will get too tall and leggy without the proper light and will have a hard time growing to a proper enough plant to then set outside.


There are plenty of perennials that can be started from seeds this month to give you a good head start for your flower beds when the threat of frost is gone. Some goods ones to consider starting now are:
purple coneflower

  • rudbeckia
  • Shasta daisy
  • yarrow
  • columbine
  • blue star
  • gaillardia
  • salvia

Bleeding hearts, Delphinium and phlox can be grown, also but you need to cold treat the seeds before trying to germinate them. Don’t know how to cold treat? It is easier than you think. Here is a video that explains the process. She is talking about a different type of flower but the same method is used to cold treat any of your seeds.

I can’t stress enough the importance of good lighting for your germinating your seeds! That is the most important part of growing your plants indoors in February so that they will be nice viable plants for transplanting into the ground later. Invest a little time and money in some good lighting and you won’t regret it. This will take a small amount of an investment but you will have it to use for years to come and the lighting will quickly pay for itself in the money you save in not having to buy plants from the local nursery in one season.