I was recently asked how to plant in clay soil.
Here are some options.
First off, kill off the grass and weeds. You can cover the area with a tarp or newspaper/cardboard or use a herbicide. Use a lawn mower with a bagger and remove all the weed seeds and waste. You don’t want to have to battle the weeds during that first year.
The easy way to plant with a clay soil base is to cover the area with 6 to 12 inches of a good soil/compost mix. You plant in the soil mix and not the clay soil. Over time, the roots and earthworms will break up the clay soil.
Another option is to plant native seeds in the fall. Make sure the seeds come in contact with the soil. The above are Asclepias tuberosa seeds I planted last fall. I then cover the seeds with a soil mix so that the seeds are covered and will germinate easily in the spring. Native plants don’t need or want good soil for growing.
If you have the time, energy and money, you can dump lots of compost onto the clay and till it in. You can then plant directly into the soil. Unfortunately, in the process of roto-tilling you will bring up dormant weed seeds and will have to battle the weeds in the spring.
The final option is to make a hole for each plant and throw away the clay soil. You can then add a potting mix to the hole when you plant. I have used a large bulb planter in the past with this technique and it works well.
When the plants are growing well, you can add mulch to help with the weeds and conserve water. I usually add a mixture of compost and mulch every year to help feed the plants and improve the soil. Note – I found out that the mixture I got was very hot and killed most of my grass in the center.
If you are putting in a new garden or you just want to know your soil composition, then a soil analysis is a good place to start.
For only $25.00 there are three places in St. Louis you can take your soil sample to have it analyzed.
This week I brought in lots of plants for a school garden, which had not been prepared in any way. Ideally, the soil would have been amended or they would have added 6 to 9 inches of top soil and compost. In this case we were dealing with soil that had landscape fabric on top – probably for years.
After taking the landscape fabric off, the soil turned out to be wet clay which would have been very tough to dig in and impossible to break up.
I had brought my heavy duty bulb planter which made short work of creating nice size holes to put in the plants. This particular model was made by Hound Dog and is an older model. Its opening tapers from 2 3/8″ to 3 1/4″. You pull on the handle to open up the bottom and release the clay. There appears to be a new model being sold which has some bad reviews. I’d advise buying one from a local store so you can return it if you have trouble.
I added potting soil at the bottom of the hole, put in my plant and added more potting soil.
This technique works very well when you have wet clay soil. You can put in lots of plants with a minimum of time and effort.
This technique works great for schools which have young kids and terrible soil. Here’s what the end result looks like.
Filed under Schools, soil
I recently had a friend by a soil mix from St. Louis Composting. It was supposed to be a mix of 50% top soil and 50% compost. She ended up getting big clumps of clay in the soil and I was disappointed in the mix. There response was this, “With the wet winter and now wet spring, it has been hard for us to pull soil out of our fields. This has led us to go to other sources of receiving the material.” Their new source seems to be more clay than anything like topsoil.
I also went to Grants View library community gardens. They have just completed their raised beds and were also filled with those large boulder like clay clumps. Gateway Greening ordered the same Garden Mix which was supposed to be 50/50 said, “They have a huge facility, so there are always variables in my experience.”
The lesson learned is this.
Go to the source of your soil and check it out before you buy it. Look at it, feel it and check the quality of what they are going to send you.
After they dump the soil on your lot, it’s too late to do anything about it. Check out the soil or soil and compost combination ahead of time and make sure they get exactly what you want.
Note – St. Louis Composting also has a product called SLC Raised Bed Mix which might be better, but is more expensive.
Filed under Schools, soil
I’ve got a school that doesn’t have room for a traditional in the ground garden, so we are going to plant in large pots. The question that comes to mind is, “What kind of soil should we put in the pots?”
Here are two solutions from two experts.
- One expert, Jesse, suggests this for a mix to fill the pots.
2/3 – potting mix – I like ProMix – BX – it has micorrhizae
1/3 compost – this provides a lot of the nutrients that the plants need. I like the Black Gold compost that you can buy at http://stlcompost.com/products-compost/
If you don’t need a large quantity they do sell it for $3.50/bag or 3 for $10.00.
Jesse does not use Osmocote or any other fertilizer, but every year he might just add extra compost to the pots.
- Another expert from a Horticulture program suggests using ProMix BX. Don’t use any other amendments, but after you put in the plant, you sprinkle Osmocote on top. There are two types of Osmocote – I buy the one with the micro-nutrients. Another tip she had was to put in an upside down pot to help take up some of the space if you want to save money on potting mix.
Below are three pots I did for a school. They are fairly large pots and are filled with Miracle
Gro potting soil plus a Miracle Gro Compost. Each pot took about a dozen plants and then some of the kids planted marigold seeds around the outside. One pot with the stake was entirely different types of milkweed. The other pots were combinations of host and nectar plants. I put in close to a whole tray of plants into each pot.
May 10, 2016 – I’m also testing out a pot at home to see how the various plants do.
Here’s a list of butterfly plants I have put into pots.
Alyssum, Bronze Fennel, Coreopsis, Echinacea, Pussy Toes, Salvia, Shasta Daisy, Tropical Milkweed, Verbena bonareinsis, Verbena trailing, Veronica.
Filed under Schools, soil
I’m going to use this page to add in information about this topic.
Here’s some good information from Gabe Brown on Mycorrhizal Fungi. One of the reasons I use Pro-Mix BX is because it has this fungi.
I noticed that they use Pro-Mix BX at Shaw Nature Reserve so that is the seed starting mix and potting soil I’m going to use for most seeds and plants.
They do make similar products, but what you want in the product is MYCORRHIZAE.
According tho their website, it improves fertilizer uptake; reduces fertilizer costs increases plant’s resistance to stresses; reduces maintenance costs.
Some products which look very similar don’t have the MYCORRHIZAE
I’be been told that the HP variation stands for High Porosity and just has more perlite. It is more expensive.
2016 – I found the BX product at the Bayer Garden Centers. $36.99 for a 3.8 cu. ft compressed bale
Note – this brand does NOT have fertilizer so you will need to add some Osmocote when you transplant.
I also found Pro-Mix at Menards, but it does not have the Mycorrhizae.