Chaparral’s June Update from the Green Thumbs

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Getting the Most from Container Gardening

by Jolene Ottosen for the Chaparral Green Thumbs

Lately, I have been talking a lot about the recent resurgence of gardening. With so many people staying closer to home and having more time on their hands, and perhaps less money to spend, gardening can be both therapeutic and economical, but digging up a portion of your yard isn’t always an option for everyone, so this month I would like to look at container gardening.

A friend recently sent me links to West Coast Seeds’ “Urban Garden Series” so I thought I would share what I learned from their article “Growing Food in Containers”.

The first thing you need to consider with regards to what can be grown in a container is the root system and the height. For example, the article mentions that the root systems of some squash can have a diameter of up to 30 feet if unrestricted and a tap root that is six to seven feet long, which helps me feel better about my lack of success with zucchini in my containers last year. This doesn’t mean you can’t grow any squash; you just need to be more judicious when choosing seeds and consider container size. Next time, I will choose a bush zucchini variety. The article also suggests that most containers won’t provide the depth that vegetables such as beets, garlic, onions, parsnips, radishes, and turnips need to grow and fully develop.

The article then goes on to list the three garden essentials:

  1. A stable soil receptacle: You can be creative or traditional with this, but it needs to be sturdy enough to hold the soil, plants, and water. I know of one thrifty farm gardener who reuses the heavy white plastic silage bags, such as the ones used for the plastic covered hay bales you sometimes see out in fields that I used to tell my children were giant marshmallows, to garden in. She simply poked holes for the seeds and watering and was left with a virtually weed free garden as the plants came up through the holes. Many of my containers are leftover mineral tubs my dad used with the cows. They might not be the prettiest ones around, but once things are growing you tend to notice the plants more than the container anyway.
  2. Proper drainage: Plants do not thrive or often survive if the roots sit in water, so you need to ensure whatever container you are using can drain. Also, be sure to consider where the drainage is going. If the containers are sitting on your deck, you may want or need something under them to capture the water to protect the surface below. For my self-wicking pots on my deck, I try to position them so that the overflow hole is turned to the edge of my deck, and the pots are positioned so they are hanging just a bit over the edge of the deck on that side.
  3. Enough depth: Containers need to be a minimum of at least 4” or 10 cm deep, but the reality is, the deeper the better to allow the plants better access to moisture and nutrients as they grow. While I have a few smaller pots for herbs or flowers, all of my vegetable planters are closer to 2’ deep.

Beyond these essentials, the article talks about the fact that pots above the ground will be warmer during the day and colder at night than those in the ground. For some heat loving plants like peppers, this is beneficial, but it also means they will dry out faster than they would in the ground and need to be watered regularly. This is where I often struggle and have found that I have the most success with larger, self-wicking containers that help the plants better survive my frequent neglect. “Gardening with Leon” online has some great tutorials on creating your own self wicking containers and I wrote about the pots I built using his method last year. Since then, I have found a streamlined version that doesn’t need landscaping fabric or a filling hose, that I will be trying this year.

Soil nutrients and adequate sunlight are also important considerations for your gardening success. Fruiting plants will need at least six to eight hours of direct sunlight each day, so be sure to place them where they can get that, or plan to move them if you need to. Most commercial potting soils will have premixed fertilizers that can meet your plants’ needs, but the article recommends supplementing that when planting, and every three to four weeks after that, with an organic fertilizer.

You also want to be sure not to overcrowd your containers. I am guilty of sometimes planting as much as I possibly can in my plot at the community garden, but a small container only has so much soil and nutrients, and crowded plants can’t get the sun they need. For example, fruiting plants like a tomato need five gallons of pot per plant. My tubs are larger than that, but unless I plant on the edges and raise my pots so the plants can hang down, I will still have the most success with one pot per plant, a fact I admittedly struggle with.

Finally, here are the plants that the article suggests will do well in container gardening.


  • Arugula
  • Bush Beans
  • Drying Beans
  • Pole Beans
  • Beets
  • Broccoli
  • Cucumbers
  • Kale
  • Lettuce
  • Mesclun and Salad Greens
  • Micro-Greens
  • Mustard Greens
  • Onions
  • Pac Choi
  • Peas
  • Potatoes
  • Spinach
  • Strawberries
  • Swiss Chard
  • Tomatoes


  • Basil
  • Chervil
  • Chives
  • Dill
  • Mint
  • Oregano
  • Parsley
  • Sage
  • Thyme


  • Alyssum
  • Calendula
  • Celosia
  • Clarkia
  • Cosmos
  • Cynoglossum
  • Iberis
  • Linum
  • Lobelia
  • Marigolds
  • Nasturtiums
  • Nemophila
  • Pansies
  • Phacelia
  • Sunflowers
  • Sweet Peas
  • Veronica

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