Broccoli Needs Good Soil
Organic Matter is Critical - The quality of the produce grown in the home vegetable garden is directly related to the health of the garden’s soil. Most garden soils lack sufficient organic matter down 8 to 12 inches. Such material begins as organic mulch which is over the season broken down and pulled down into the soil by earthworms and other soil creatures. That is why we recommend having 2 to 4 inches of organic mulch on the surface of the garden all 365 days of the year.
Bring Life Back To The Soil – Soils in new gardens and even soils in many established gardens usually lack much of the microbial life found in healthy soils in the woods or in undisturbed prairies. There is now a new soil amendment the actually contains all the common strains of bacteria and other microscopic critters found in good soil. The quality of your broccoli will be directly related to the quality of the soil in which it grows.
Amendments In Planting or Transplanting
There are a number of products at the garden center that will help your newly planted or transplanted plants deal better with the stress inherent in the planting process. All healthy plants have beneficial fungi, called mycorrhizal fungi, living on their roots. You can buy these valuable additions to your plant’s ecosystem. See the file describing Using Micorrhizae When Planting.
In addition, there are a number of products such as seaweed, compost tea, and beneficial soil microbes that when added to the planting process will help your newly established plants get going faster. See the file New Technology In Plant Growth Activators
How To Plant Broccoli
If you choose to start your broccoli from seed indoors We offer a broad range of seed starting equipment and supplies in Yardener's Tool Shed; click here
Whether you grow your own seedlings by planting broccoli seeds indoors under lights several weeks before the last frost in your area, or you buy seedlings from the garden center or from mail-order catalogs, it is important to plant them outdoors correctly. Seedlings should be at least four weeks old and have two to four leaves and a stem half as thick as a pencil. Plant them about two to three weeks before the expected last frost date for your area. While they can handle cool weather, it is best to protect them from a surprise late frost. Be prepared to cover the tender plants temporarily with white polyspun garden fleece, plastic water insulated collars, newspaper cloches, or a cold frame.
Planting Steps
1. Plant broccoli seedlings on an overcast day, or late in the afternoon, to reduce their exposure to hot sun while they recover from transplant shock. Wait until the soil is fairly dry and can be dug without making sticky clumps. Prepare the garden bed by digging into the soil from 6 to 8 inches deep with a trowel or shovel. Turn over the soil to loosen it, breaking up any clumps and removing rocks and debris. This is a good time to sprinkle some all-purpose slow-acting granular fertilizer on the soil and mix it in. Smooth and level the planting area.
2. Dig holes in the planting bed about 12 inches apart--further if you want the largest possible broccoli heads. Make them a little deeper than the containers the seedlings are in. Tip the seedlings gently out of their little containers and set each plant in its hole at the level of the first set of leaves--about 1/2 to 1 inch deeper than they grew in their indoor containers. This causes the plants to develop roots all along the submerged part of the stem. It also keeps the plants erect as they mature and allows them to build a strong root system.
3. Gently firm the soil around the seedling stems and water the area. If you have put slow-acting fertilizer in the soil already, do not fertilize the seedlings further at this time. Adding some seaweed- or kelp-based tonic, to the water helps ease the shock of transplanting and get the seedlings growing faster. It is optional, not essential.
Planting Tricks
Sneaking Spacing Of Seedlings: The size of the broccoli head and the number of side shoots it produces after the main head is harvested is related to how closely you plant the seedlings. To get the maximum size head and the most side shoots afterwards place your broccoli 18 inches apart. If you just want to harvest lots of broccoli at one time (perhaps for freezing) and then plant something else in that area, space the plants 10 to 12 inches apart. You’ll get smaller heads but more pounds of broccoli per square foot of space.
Getting A Double Harvest: At planting time or shortly afterward consider spreading a layer of organic material such as straw or chopped leaves on the soil around and between the young plants. This will discourage weeds, retain soil moisture and cool the soil as spring warms up. Alternatively, interplanting lettuce seedlings or radishes, which also like to grow in cool weather, around the base of the broccoli plants provides a second harvest from the same space in the garden. Note: Use lettuce seedlings (not seeds) because broccoli plants exude a chemical called thiocyanate that retards sprouting of plants with very small seeds, such as lettuce and spinach. However, radishes don’t seem to mind.
Basics For Fall Planting
Fall provides a second cool season when broccoli thrives in the garden. During this season plants typically provide the most food from their side shoots rather than from their large main head. Plan to start harvesting at least a month before killing frost in your area, so start new seedlings in late June or early July. This time you can start them outdoors in the North, but raising them indoors protects them from insect and critter problems at their most vulnerable stage. It is worth the two week setback they suffer upon transplanting outdoors which directly seeded plants do not experience.
After four weeks, plant seedlings out in the garden and immediately cover them with either shade cloth or garden fleece raised above the tops of the plants with some kind of support. This protects them from direct sun and keeps the soil a bit cooler. On really hot days, water the seedlings at noon to cool the soil even more. Later, if you protect your broccoli plants with fleece as frost approaches, you can usually continue harvesting for several weeks past killing frost. Many people mistakenly plant fall broccoli and fall cauliflower at the same time. Broccoli should be transplanted several weeks earlier than cauliflower.
Broccoli In Containers
Broccoli grows well in containers. Choose one that is at least 12 inches wide and at least 12 inches deep. Make sure that it has a drainage hole in the bottom. Fill it with a soilless potting mix and plant one or two broccoli plants slightly deeper than the containers they grew in as seedlings. Either mix in some all-purpose slow-acting granular fertilizer to the planting medium at this time, or plan to add dilute liquid fertilizer periodically to the watering can when you water. Plants in containers dry out very quickly, make sure you water faithfully.
To beautify your broccoli containers, plant a ring of white alyssum around their stems to compliment the vegetable’s gray-green foliage. Then add some pink petunias around the outside edge of the container to spill over the edges, soften and brighten the whole container.
