Learn About Old Soil vs. New Soil
OLD SOIL VS. NEW SOIL
If disease was a problem last year, using the same potting soil can be a recipe for disaster. Viruses, bacteria, and fungi will live on in the potting medium long after the plants have withered away. While it may be possible to destroy these lurking pathogens, it's not worth the risk.
With thoughtful handling, you can reuse potting soil in next year's containers, or use it to solve other gardening problems. The first step is to let used potting soil dry out, either in pots or dumped into a wheelbarrow or onto a tarp.
When your flowers fade, and the temperatures drop, it's time to empty your containers and put them away for the winter. It's tempting to keep and reuse the old potting soil. Lightweight potting soil mix doesn't last forever. Plants use up most nutrients in it as they grow, and the mix can become compacted and filled with roots. Sometimes pests, diseases, and weeds can take up residence, ready to pop back up when you replant in the mix. However, you can remedy each of these issues and get another use out of your potting soil with a little extra work.
That unusual occurrence doesn't duplicate itself because tomatoes will deplete the soil of nutrients quickly. We wouldn't risk just winging it if this is your first year growing, as you can do a lot to ensure you get a fabulous and healthy tomato garden.
Tomatoes are extremely vulnerable to disease, especially soil-borne disease. They also require a large amount of nutrients from the soil for strong growth. Nutrients that are easily depleted when you continue growing the same crop in the same soil year after year.
It's generally fine to reuse good source organic potting soil if whatever you were growing in it was healthy. If you did notice pests or diseases on your plants, it's best to sterilize the soil mix to avoid infecting next year's plants. First, remove any roots, grubs, leaves, and other debris from the old potting soil. Then, decide on the best method for banishing microbes and insects.
One technique for sterilizing soil is called solarizing. It involves putting old potting soil in lidded, five-gallon buckets ($7.98 The Home Depot) or black plastic bags that are tightly tied shut and leaving them in the sun for 4-6 weeks. The heat builds up inside the buckets or bags just enough to kill bugs and pathogens.
You also can sterilize old potting soil in your oven. Place it in an oven-safe pan, cover with foil, and bake it at 180 to 200 degrees Fahrenheit for 30 minutes. (if will create earthy smell most likely) It's also important to check the soil temperature with a candy or meat thermometer ($22, Williams Sonoma) to make sure it stays below 200 degrees. Higher temperatures can release toxins. When it's done, take the soil out of the oven and keep it covered until it cools.
Microwaving is another option. Put old, moistened potting soil in quart-size, microwavable containers. Cover them with microwavable lids—never use foil—that you can poke ventilation holes in or can leave cracked to allow steam to escape. Heat at full power for about 90 seconds per two pounds of soil. Remove the containers, cover the vent holes with tape, and let the soil cool completely before using it.
Once your old potting soil has been sterilized, you'll need to replenish its nutrients. You can do this by combining equal parts of new potting soil with the old and adding a dose of slow release organic fertilizer such as our Organic Worm Castings
Besides adding nutrients that your plant need- both the fresh potting soil and compost will help keep the mix from compacting.
If you're storing your refreshed potting soil until it's time to plant again, keep it in covered buckets or clean trash cans ($36, Walmart) or tubs with lids ($8, Target).
WHAT TO DO WITH USED POTTING SOIL
Reuse your clean potting soil in containers for vegetables, flowers, houseplants, or whatever you'd like to grow. If you're not up for sterilizing and refreshing old potting soil, you still can put it to use instead of throwing it out. It can be dumped directly out of your containers and into established beds and borders. I like to use mine in my raised beds or wherever I need to fill in holes or eroded areas in my yard. It can also be mixed into compost piles. The old potting soil you reuse can help you save money for what all gardeners want: more plants.
Yes, you can use the old soil in your pots, planters and raised beds. Just start the season with a special boost that ensures good results. With a couple ingredients, you can transform depleted soil into fertile ground for whatever you want to plant.
Top it off:
If the level of soil has dropped more then 4”, add fresh organic garden planting mix, also known as potting mix such as our Happy Half Gwen’s and KelpMyco Mix
Ideally, the soil comes to flushed with the rim of the planter or raised bed. Use a fork or hand tool to blend the new soil into the old soil.
If you just want to recharge it:
Measure the square footage of your raised bed or pot to figure out how much of the two "secret ingredients" you need for your bed.
Sprinkle the Mycorrhizal Endo Ecto, and Organic Worm castings onto the soil surface (You can also add some composted organic Happy Cow, alpaca, chicken even rabbit manure if possible). Use a hoe or cultivating tool to incorporate the ingredients into the top few inches of soil.
Plant, feed, and repeat! Now sow seeds or plant transplants into your raised bed, and then stand back. Great results are sure to follow. During the season, keep your plants happy by feeding them regularly.