Is it wise to reuse potting soil?

Question

The potting soil in question is in medium to large sized pots that had/have tomatoes or small fruit trees in them.

Answer 1

The only two problems I can think of would be disease and nutrients. There are some diseases (eg. fungi and nematodes) which will linger in soil, so you really need to treat the soil or discard it to somewhere where the disease is not a problem (ie. a different kind of plant).

As for nutrients, these could be topped up with liquid feed or top dressing. I find potting compost settles / compacts quite a bit so there's usually space for top dressing each year. I also re-use potting compost by putting it on raised beds or filling small hollows in the lawn. It isn't the best medium for the latter, but every little bit helps.

Answer 2

It all depends on what was initially potted inside of the soil, to add onto @winwaed you can actually boil some water and pour it into the soil to kill any bacteria or disease. The other thing you can do is use some fungicide to get rid of anything harmful.

Although top soil is fairly inexpensive its a major profit margin for these garden retailers like home depot, lowes, randazzo's, etc. They want people to toss the stuff out and buy new soil each and every year. To me this is a total waste of money and another way to make a dollar off of you. To you a bag of decent top soil is a mere 3-4 bucks...but multiply that by thousands of people buying that stuff and this could be just for one store!

You can always mix it up with some new soil if you still insist on buying new top soil.

Answer 3

I've read (I think in Rodale's Organic Encyclopedia) that you don't want to till potting soil into your garden, but certainly can use it to help your compost pile.

You can make your own potting soil (even using dirt in the microwave). Which is a good way to save money.

Answer 4

• Crop rotation My grandparents had а large garden beside the vineyard, that they cared about long years. Every spring, they reshaped the garden - putting the tomatoes, cucumbers, pumpkins, carrots, onion, cabbage and other goodies in new places. They told me this is because every plant uses some same assortiment of nutrients in the soil. Planting the same kind of plant in the same spot for several concessive years would exhaust the soil, they explained. Later, at the university, the teacher in Engineering Ecology told us planting the same crops in the same place is one of the biggest problems of contemporary agriculture.

• Adding compost I have read that compost not only supplies the soil with nutrients, but also aids texture. This summer is my second year of balcony gardening. I use the same soil as wast year, mixed 3:1 with compost. I compost most of what I harvest and don't use (stems, leaves). Everything is growing fast & healthy for now, so let's hope this works out forever :D I would really love to be closer to sustainable.