Container Gardening
How much soil do I need for my container?
This information came from many different places. No one seems to agree, so here is what I could find. I listed the lowest and highest amounts that I found and the only amount I found for some sizes.
Pot Size | Soil Amount |
4 inches | ½ quart |
6 inches | 1 ½ to 2 ½ quarts |
8 inches | 4 to 6 quarts |
10 inches | 9 to 10 quarts |
12 inches | 14 to 18 quarts |
14 inches | 18 to 20 quarts |
16 inches | 22 quarts |
20 inches | 26 to 28 quarts |
24 inches | 36 quarts |
30 inches | 72 quarts |
36 inches | 96 quarts |
Preparing and Choosing Containers
Use Anything That Will Hold Soil
Recycle buckets, large black buckets from shrubs and trees, bathtubs, wheelbarrows, barbeques, half gallon and gallon milk jugs, juice containers, 2 liter soda bottles and even plastic grocery bags. Be creative. Buy planting containers if you must. If using a container that you can see through then do something to darken it. Use paint that will adhere to plastic, line it with black plastic or card stock weight cardboard, like it did with my potato tote, or wrap the plastic or card stock on the outside and secure it with elastic bands or twine.
Make sure all containers have drainage holes for best results. I say for best results, because I am going to line my antique wheelbarrows with plastic to protect them and plant in them that way. They will just have to be watched more closely.
Place something over large holes to keep the soil in. Use paper, newspaper, or cloth. These will keep insects from crawling in through the holes also. If you are recycling buckets, totes, or other container make sure there are drainage holes in the bottom. Use a sharp object or drill to make several holes.
Preparing the containers for planting
Sterilize all containers
Remove as much soil as easily possible from your recycled plant containers. They don’t have to be super clean, but they must be sterilized. Mix one part plain bleach to nine parts water and rinse your containers. Make sure all surfaces are rinsed. Allow to dry. (If I am drying them indoors I rinse again with plain water, so I don’t have any bleach drip on my towels)
Make a soilless mixture or add potting or planting soil to plant in
To make a soilless mixture I use one part peat moss, one part vermiculite, and one part perlite. Put all of these into a large container and mix. Add enough warm water to hold the mixture together. The peat moss will float if you use cold water. If you use a potting or planting soil make sure is can be used in pots. Some planting soils say they are not suitable for containers. Some potting soils say they must be mixed with soil from your yard. READ BEFORE YOU BUY.
Filling your planting containers
Depending on the size of your container you may want to put them in their permanent location before starting this process.
Push the mixture in tight enough to get rid of all air pockets. Fill about halfway and add plenty of water. Let that water soak in for a while and add more soil and press the mixture in again. Add plenty of water again. Don’t fill to the top yet if planting plants. The final soil depth will be about 2 inches from the top.
Planting your plants
Preparing plants for planting
Remove the plant from the nursery pot and gently loosen the roots. Untangle any that have grown in a spiral around the inside of the pot.
Planting the plant
If the plant you are planting has a current soil depth of 4 inches then the soil in the new pot should be 6 inches from the rim. Adjust this height match what you are planting. Add or remove enough soil to get the depth you need. Spread out the roots and set the plant in the new pot. Add 4 more inches (adjust as needed here too) of soil and press it in to remove all air pockets, add soil and press in again as many times as needed to get the plant's soil and the new soil to the same level. Water again.
Planting seeds
Plant seeds three to four times the depth of the seed thickness. What is the thickness? Lay your seed on your counter, table, or wherever you are working. The way it lays by itself is the thickness (height) and the way you are going to plant it. You may want to cover your pots with plastic until they germinate. Containers seem to dry out fast.
How many plants can each container hold
Container size is based on store bought planting pots when listed in inches not recycled containers, so adjust to your container’s measurements. I could not find very good information from books or on the internet. The beets, carrots, lettuce, and spinach are what I would do. These are just suggestions to help you have something to work from. Read the seed packets and follow the spacing on them. Keep the outer most seeds ½ of the spacing or more away from the container’s edge.
Plant | Quantity | Container Size |
Beets | 3 to 4 plants | 1 gallon |
Beans (Bush) | 2 to 3 plants | 1 gallon |
Broccoli | 1 plant | 14 inch or 5 gallon |
Cabbage | 1 to 2 plants | 14 inch or 5 gallon |
Carrots | 3 to 4 plants | 1 gallon |
Cauliflower | 1 plant | 14 inch or 5 gallon |
Cucumber (Bush) | 1 plant | 14 inch or 5 gallon |
Eggplant | 1 plant | 14 inch or 5 gallon |
Herb | 1 plant | 8 inch |
Lettuce | 1 plant | 8 inch |
Spinach | 1 plant | 8 inch |
Squash (Summer) | 1 plant | 12 inch |
Tomato | 1 plant | 14 inch or 5 gallon |
Watering
You will need to water daily. Plants in containers dry out fast. Water early in the morning whenever possible. Keep gallon milk jugs filled with water near the plants for quick and easy watering. As the plants grow you may need to water 2 or 3 times a day. For 12 inch or larger containers insert you index finger up to the second knuckle, which is about 2 inches. For an 8 inch container insert your index finger up to the first knuckle. If the soil is dry then the container needs water. If you don’t want to get soil under your fingernails then try a moisture/water meter for houseplants. Mulching your plants will help the containers retain water.
Protecting your plants from critters
Cover the soil with mulch, wrap the container with wire, or set the container up where critters cannot access it.
Mulch
Try using small rocks, grass clippings (containing no weed killers), newspaper (you may need a few rocks to hold it down), pine needles, coffee grounds or wood chips (not cedar and watch to make sure this doesn’t suck the water out of the containers).
Protecting your Plants from cold temperatures and winds
Move containers into a protected corner if possible. If the container is wrapped in wire then wrap plastic, row cover or a sheet around the wire. Use walls of water, tomato cages wrapped the same as the wire mentioned above or just cover the container with row cover or a sheet. Place cardboard boxes or milk jugs over the plants. Here is a time to be creative again. Don’t forget to uncover them or your plants may die from the heat.
