Finding the Ideal Broccoli Spacing
Broccoli plants need ample room in the garden for the best crop yields. Ideally, you'll want to space broccoli plants no less than 18 inches apart. If you are planting multiple rows of broccoli, each row should be at least three feet apart. You can try a closer broccoli spacing, but crowding your plants will reduce the size of the heads they produce and lower your overall yields. If you don't have a lot of room in your garden or any real garden space at all, you can successfully grow broccoli individual pots.
Spacing in the Garden
Broccoli is a pretty big plant, growing up to three feet tall and up to three feet wide, according to Cornell University's Growing Guide.
The plant needs plenty of room in the garden for proper root develop and for the full development of the broccoli crowns or heads. You have a number of options when it comes planting and spacing broccoli in your garden.
Spacing When Starting Seeds
There are two ways to start broccoli from seed in your garden. The method you choose determines the initial broccoli spacing you'll need.
When you direct sow broccoli, you plant the seeds right in the soil where the plant will eventually grow.
In the video above, from Grow Organic Peaceful Valley, the gardener demonstrates how to plant broccoli seeds in your garden. You'll want to space the seeds about three inches apart. Each see should be planted about a half inch deep.
If you live in an area where the temperatures get hot quickly in the spring and summer, you'll want to get a jump on the broccoli season by starting your seeds indoors, in small pots. Check the date of the last frost in your neck of the woods, and aim to plant five or six weeks before that.
You can purchase special seed starting cell planters or use clean, empty yogurt cups or even an empty egg carton (one seed per cup).
When you direct sow broccoli, you space the seeds a few inches apart. That's because there is a chance that not all of your broccoli seeds will actually germinate and produce a plant.
Even if just a few of the seeds germinate, it's likely that the seedlings will be too close together for the plants to actually thrive and grow into a full-size broccoli plant.
You'll need to thin the plants to get the spacing right. In the garden, broccoli plants should be spaced between 18 and 24 inches apart. If you are planting more than one row broccoli, each row should be at least 36 inches away from the next row.
Choosing the Plants to Remove
The above video from PadreSol shows you how to decide which broccoli plants to remove when you are thinning the patch and how to remove the plants. For the best harvest possible, you want to leave the healthiest looking plants in the garden and remove those that look stunted or that look sickly.
Use a sharp knife or gardening shears to cut down the plants you're removing. If you pull the plants out by the roots, your risk disturbing the root system of the broccoli you are leaving in the garden.
Planting Broccoli Seedlings
If you started your broccoli plants indoors, they are ready to be planted in your garden when they have a few sets of leaves. Space the transplants 18 to 24 inches apart in a row. To plant the seedlings, dig a small hole in the soil that is slightly larger than the rootball of the plant.
According to the University of Illinois Extension, you want to plant broccoli seedlings a bit deeper than you originally grew them. That means the top of the root ball should be just beneath the top of the soil.
Growing Broccoli In a Tight Space
Although leaving at least 18 inches between each broccoli plant is ideal, it is possible to grow the plants a bit more closely together. For example, according to Utah State University's Cooperative Extension, you leave just one foot of space on all sides of the broccoli plant if you need to.
The more cramped growing conditions will affect your yields. Since the plants won't have room to spread out fully, you can expect to see smaller broccoli heads. The plants are also likely to produce smaller or fewer side shoots after the main head is harvested.
Growing your plants close together can also put them at greater risk for disease or for pest problems. The more cramped conditions are, the less airflow there is between plants, which can create an ideal environment for fungi or bacteria to grow.
Spacing in Containers
You can grow broccoli in containers to save space in your in-ground garden or if you only have access to a patio or deck. The rules for broccoli spacing are similar in containers as they are in the garden. Each plant will need ample space to grow and thrive.
The size of the container you choose determines how well your broccoli will grow. Use the same space requirements for in-ground broccoli when choosing your containers: look for pots that are at least 18 inches in diameter. To make sure the pot will hold enough soil to allow for root growth and good nutrition, Bonnie Plants recommends looking for a container that has a volume of at least 5 gallons.
If you're going to grow several broccoli plants in containers, leave enough room between the pots for the plants to grow. You can try to grow a few plants in the same container, provided the container is large enough. For example, you might be able to successfully grow two or three broccoli plants in a 15-gallon pot that's about 36 inches wide.
Although you can grow broccoli in close quarters, for the best results, you'll want to give each plant plenty of room to grow. The more space a plant has to spread out in, the more likely it is to produce delicious broccoli for you to harvest and eat.