Broccoli (Brassica oleracea var. italica) is a popular vegetable with home gardeners. It grows best at temperatures between 65-75 degrees F, so is considered a cool-season crop. Most people who grow broccoli in their garden buy transplants. However, you may be wondering “Can you plant broccoli seeds straight in the ground?”
Broccoli can be grown from seed sown directly in the ground during some parts of the year. Here is what you need to know to grow broccoli from seeds planted directly in the ground.
Can You Plant Broccoli Seeds Directly In The Ground?
Yes, you can plant broccoli from seed. This is generally done for the fall crop of broccoli. In the spring, transplants are best. You plant the broccoli seeds in a trench 1/4th to ½ inches deep and cover the trench. The seeds usually germinate in four to seven days.
Preparing To Plant Broccoli Seeds
Before you can plant your broccoli seeds, you need to prepare the soil so the seeds can grow. Here are the steps you need to take to get ready to plant.
- Remove any plant debris and mulch from the soil.
- Till the soil to a depth of six inches.
- Put a three-inch layer of compost on the soil.
- Mix the compost and soil together.
- Make rows where the seeds will be growing.
- Spread a balanced fertilizer for vegetables, such as a 10-10-10, over the seedbed and mix it in the first three inches of the soil.
- Rake the tops of the rows smooth.
How Do I Plant Broccoli Seeds?
Now that your seedbed is ready, it is easy to plant broccoli seeds.
- Make a trench that is ¼ to ½ inch deep on the top of the row.
- Place three broccoli seeds in the trench every eight to ten inches.
- Fill the trench in.
- Water the seeds. Use caution not to wash the dirt off the seeds.
- Thin plants to one every eight to ten inches once the seedlings appear.
Common Problems When Growing Broccoli Directly In The Ground
According to the Minnesota Extension Service, broccoli seedlings are fragile at first. They need some special care during the first few weeks of their life until they grow stronger. Here are some common problems and their solutions.
From the time broccoli seeds are planted until they reach about six inches high, it is very important to keep the seedbed moist. Seedlings do not have well-developed roots at this stage so can’t draw in the water below the surface of the dirt well. If the seedlings dry out, they usually die.
The seedbed should be moist, not wet. If you pick up a handful of dirt and squeeze it, then open your hand, and the soil should stay together. If you get water out of the soil, it is too wet. If the soil crumbles when you open your hand, it is too dry.
Wind can dehydrate seedlings quickly. If the wind is strong enough, it can blow the seedlings over. Covering the seedlings with a row cover when they are young can protect them.
You will need shallow hoops that are taller than the plants to put the row cover over. Choose a white row cover so the sun can penetrate it.
Be sure the row cover is properly anchored, or it will be worse than no cover at all.
Hard rains can pound seedlings into the ground. They can also wash the seeds away if the rain falls soon after you plant your broccoli seeds. A row cover on hoops will help soften the rain so it doesn’t hurt the plants.
Lots of insects feed on broccoli plants. Seedlings are especially vulnerable. Using a row cover to keep them out until the seedlings get older is helpful.
Most of the early diseases broccoli seedlings get are caused by overwatering. Keep soil moist, not soggy. Damping-off, caused by a fungus, is when the seeds fall over. They have a rotten spot at the soil level. This is fatal. Let the seedbed dry out a few days before replanting.
Broccoli are heavy feeders. That means they need frequent fertilizing. However, they need the correct fertilizer. It is best to get a soil test and base your fertilizing on that. However, if you do not have a soil test, you can still fertilize.
When the seedlings are six inches tall, spread a 5-10-15 fertilizer along the row six inches to the side of the plants. Continue fertilizing with 5-10-15 every four weeks.
Too much nitrogen and the plants will grow lots of foliage and few heads. Always water the fertilizer in so it does not burn the plants.
Bolting is when the broccoli plant prematurely grows a flower stalk. The broccoli heads are ruined once this happens.
It typically happens because there is a period of a week to ten days of cold after a warm spell. It also happens when the plant gets too hot.
If you start to see a stalk grow in the center of the plant above the head, harvest the head immediately.
Frequently Asked Questions
Here are the answers to the most frequently asked questions about seeding broccoli directly in the ground.
Do I need to soak broccoli seeds before planting?
No, do not soak the seeds first. They will rot if you do.
When can broccoli seedlings go outside?
In the spring, broccoli seedlings should go out when they are six to eight weeks old. In the late summer, they should be four to six weeks old.
Why is my broccoli only growing leaves?
You fertilized it with too much nitrogen. While all plants need some nitrogen, too much causes the plant to grow leaves but not heads.
When do I start seed indoors?
In the spring, start seeds six to eight weeks before they need to go into the ground. For the fall crop, start the seeds indoors four to six weeks before the transplant date.
In conclusion, you can grow broccoli by planting the seeds directly in the ground. The seedlings are vulnerable to wind, rain, insects, and diseases the first month after they are planted. Using a row cover for the first month helps protect the seedlings until they grow enough to handle these challenges.