Remove and replace soil?

[Janet Macunovich 32]

This from reader D.L.:

Love the work you do...

I moved from a big garden last fall. My question is preparing my soil for new flower beds. Soil is heavy clay and I want to have a mix of small shrubs and flowers especially Dahlias. I face south so that is good. Should I have someone come in and dig down about 12 inches, remove the clay and replace it with good top soil and manure. I want to make it easy for me to dig and move things around. I'm working with  approx. space of 12x15 feet. Thanks for your input.

 

If you can have the soil replaced that is probably ideal. Could be the soil that is there is not bad stuff, just packed down from construction. However, you can't be sure of that without a soil test to determine its fertility, and then it would still need considerable work to loosen that soil (and remove the resulting overage -- as loosening means adding air space).

 

Two things to be very careful of: If the area is excavated with power equipment, have the resulting glazed bottom of the hole broken manually before it's backfilled.

 

Check the drainage after excavation and before backfill. If the drainage is not good at the bottom of the excavation -- good enough to take all that will be falling into that hole from all around the hole as well as in the bed itself, have a drain put in before the bed is backfilled Otherwise it will be a bathtub, and rot roots...

 

Use a 50-50 planting mix -- screened sandy topsoil mixed with compost or peat 50/50. More on this in two of our What's Coming Up issues:

             https://gardenatoz.org/media/14774/WhatsUp34.pdf (see page 4)

https://gardenatoz.org/media/14843/WhatsUp89.pdf (page 2)

 

We're posting your question, this preliminary answer and other things we think of on our Forum.

 

Keep an eye here for the additional things we think of, and other gardeners' input.

Thanks for writing, and for your kind words. They make everything we do worthwhile.

Janet & Steven

[Your Letters 2]

What soil (or combination) would you recommend for a new construction?  The builder of my daughter's new home, back filled around the foundation with coarse construction sand and not any soil.  In some areas to the depth of 4' or more.

My thoughts are to remove a good 2' of the sand and replace with a top soil/compost mix.  What do you think?

 

My plan is to leave about 12-18" near the foundation, then remove much of the rest in the designated garden area. The sand extends about 30 feet (or more) around the whole house leveling off to meet the original farmers field. They are on a well system so fear plantings would need more constant watering if planted in sand alone. I'm not a fan of using top soil, since in most cases its junk dirt, hence why I want to use a composted mix.

Do you have any tips on how to shop for a good compost? When you grab it with your hand should it easily fall apart?

S.B.

[Janet Macunovich 32]

I'd leave the sand there. It is not at all bad for plants to grow in (one of the world's largest perennial growers has hundreds of acres of sand farm perennials in west Michigan). More important, it is essential to keeping the foundation dry. Nothing needs to be planted within 18" or two feet of the foundation. Plants set 24" out will spread to the side toward the foundaton as far as is good for them, and people do need to walk occasionally next to the building to do maintenance.

 

We buy 50-50 mix or "planting mix" when we must buy soil. 50-50 is supposedly 50% peat 50% sandy loam, sifted together. We always look at it first before we buy because there is no quality control on soil. Planting mix is supposed to be compost plus sandy loam. We look at that before we buy, too.

 

If the sand layer out into the yard is only a few inches deep and it is not hard compacted, leave it. The roots will grow into and below it. No sense making yourself work. Choose a mulch that will degrade and it will quickly modify the sand. We had pure sand on a property we helped to garden, adjacent to Sleeping Bear Dunes. Everything there grew wonderfully right from the get go and in 15 years was dark 10" deep.