How to Grow Broccoli in Containers
Growing Broccoli in Pots
Having maintained container gardens for many years, it never fails to amaze me how many people are still under the impression that this style of gardening is limited only to growing small herbs and ornamentals. For those of you out there that feel this way, you haven't the slightest clue as to what you've been missing out on!
In fact, if the proper planning is done to maximize space, container gardening can be a sustainable way to provide yourself with edible fruits and vegetables throughout the season. Even larger crops like broccoli can be easily tamed to grow successfully in a pot. This brings us to our topic of the day: broccoli in a container garden. Come learn the basics to planting, growing, and harvesting broccoli in containers.
Basic Broccoli Necessities
- Containers: Since broccoli is a larger and heavier feeding vegetable crop, a container size of at least three gallons should be provided for every broccoli plant grown.
- Potting Soil: As a heavy feeder, broccoli will also need a potting soil that is high in nutrition. An organic potting soil that has been amended with a good amount of nutritious compost should be sought. Besides nutrition, broccoli also prefers the soil to be light, well aerated and have good drainage properties.
- Fertilizer: Generally speaking, fertilizer is not as important. If you started off with a premium potting soil, there should only be a need to fertilize your broccoli plants once or twice during their life cycle. For this, I recommend an all-purpose organic fertilizer with the addition of micro-nutrients such as boron and magnesium.
- Sunlight: Although broccoli is a larger and fast-growing vegetable crop, its need for direct sunlight is a little less than many other similar sized plants. Shade tolerant to a certain degree, broccoli plants will thrive with a minimum of 8 hours of direct sunlight daily.
- Temperature: Broccoli tends to bolt (flower) when the temperatures rise above 75 degrees Fahrenheit. When broccoli bolts, there is no harvestable produce to be had. To keep your broccoli plants producing, grow only in the cooler temperatures of spring and autumn.
Growing Broccoli from Seed
Starting your garden with store-bought broccoli transplants can be a great way to grow, but I much prefer starting my plants from seed. With seeds, you have more control over the variety grown, germination conditions, as well as planting and transplanting dates. Here's how to grow broccoli from seed:
Choose Fast-Maturing Broccoli Varieties
In order to maintain an efficient container garden, it's important to select fast maturing broccoli varieties. By selecting speedy cultivars such as Atlantic, De Cicco, or Waltham #29, you'll be able to harvest full size broccoli heads in as little as 50-65 days from sprouting! Quick growing cycles like these will free up your containers for subsequent plantings.
How to Plant Broccoli From Seed
- Start germinating broccoli seeds indoors, 4-7 weeks before your area's average last frost. The seedlings will be grown indoors only for a short period of time, after which they'll be transplanted to an outdoor container, 2-3 weeks before the average last frost.
- Fill seedling cups with potting soil. Plant two broccoli seeds per container at a depth of 1/4-1/2 inch deep. Cover and water thoroughly. Place in a warm area and keep the soil moist, but not drenched.
- The seeds should germinate within 5-10 days. At this point, move your new seedlings to a well-lit area. South facing windowsills or artificial grow lighting will do fine. If both seeds in a container sprouted, thin out the smaller of the two. The whole point to planting two seeds is to be sure that at least one will sprout.
- For the next 3-4 weeks, keep the soil evenly moist and provide plenty of light for the seedlings.
Transplanting & Hardening Off
Once your seedlings have reached an age of 3-4 weeks, they will need to be moved to their final container and their new outdoor home. While transplanting can be done in a matter of minutes, the transition from indoors to out takes a bit more time. This transition can better be described as the process of hardening off, which is essentially the practice of acclimating your plants to the outdoor environment.
How to Transplant and Harden Off
- Transplant each broccoli plant from its seedling cup to their final three-gallon containers.
- Starting three weeks before your average last frost, begin to harden off your broccoli plants. Basically, you'll want to take your broccoli plants outside for an hour to start, then each following day increase the amount of time they spend outside.
- Within two weeks time, your broccoli plants should be fully acclimated and be spending their whole day outside. At this point, the plants should only be brought indoors if the temperature is expected to drop below freezing.
Caring for Growing Broccoli
Once your broccoli plants are situated in their outdoor containers, there's really little you need to do except water and wait! Follow these basic measures and you'll have broccoli crowns in no time:
- Watering: Just like the seedlings, maturing broccoli plants also prefer soil that is thoroughly moist. Take caution not to over water the plants though, as root problems and rot can easily set in. Since larger containers generally do a better job of retaining moisture, I've found that watering every other day, or every other two days to be the best watering regimen.
- Fertilizing: As I had mentioned before in this article, fertilizing is really not necessary, so long as you started with a nutritious potting soil. If you do feel the need to fertilize, applying a single application one week after transplanting the broccoli to their final containers is the time to do so. This will boost root production and give your broccoli a jump start on producing crowns.
Harvesting Container Broccoli
Assuming that all has gone as planned, your broccoli plants should be ready to harvest in 50-70 days from seed. This means that you'll have harvestable broccoli in 3-4 weeks after transplanting seedlings outdoors! The great part with broccoli is that it can be harvested multiple times before the summer heat causes it to flower. Here's how to get the maximum productivity from your broccoli plants:
- Main Head Harvest #1: The initial or main head will be the first harvestable part of your broccoli. For container gown broccoli plants, the main head will be anywhere from 3-6 inches in diameter at the time of harvest. The outer florets will have reached a size closest to the thickness of a pencil. The best tasting heads will be a dark green color and will have no signs of bolting (flowering). If you notice any of the florets beginning to flower, harvest the head right away. To harvest the main head, use a sharp knife and make one swift cut through the stem approximately 5-6 inches below the head.
- Side Shoots Harvest #2: If the harvesting of the main head was done correctly and the heat of the summer hasn't quite set in yet, your broccoli plants should grow a fair amount of side shoots. These are basically smaller or baby heads of broccoli. Look for the same indications on when to harvest, and cut them from the plant in the same matter. Generally, you'll be able to harvest these side heads a couple to a few weeks after the initial head was taken. To speed the production of side shoots, fertilize with another application at the time when you cut the main head.
Have you grown broccoli? If so, which variety?
That just about sums it up! Once you've harvested the last of your spring heads of broccoli, you can replant the container with a vegetable that is more suited to the heat of the summer. For a fall crop of broccoli, repeat the process, but this time start 90-100 days before your expected first frost of autumn. Thank you for reading my article on container gardening broccoli. Please leave me any suggestions or questions you may have! Good luck with your garden!