Garden Rule:
Do Some Seeds Need To Be Direct Sown?

"Don't Start 'x' Vegetable Seeds Indoors" Some vegetable seeds are typically sown directly into the ground. This is an easy way to start your crops. On the other hand, starting seedlings indoors may be advantageous. But you may fear doing so if a seed packet warns: "When to start indoors: Not recommended." Classic examples of direct sown vegetables are melons, squash, corn, beans, peas, carrots, radishes, beets and spinach. Even squash and melons may not be advised for starting indoors. Can you break this rule? Why might seedling transplants work better than direct sown seeds?

Why Is It Better to Direct Sow Seeds In the Ground?

In concept, I absolutely love the idea of directly sowing seeds into the ground. It's so much easier than managing a bunch of indoor seedlings. Direct sown plants don't need hardened off and they are perfectly adapted to their growing location upon germination. They don't require potting mix or tedious watering schedules. And they don't take up any precious real estate under my grow lights. Some perennial seeds like lavender can be sown in the Fall, allowing then to undergo stratification during the Winter. They'll emerge at just the right time once the weather is right. Direct sown seeds have the healthiest, most natural root structures which might include an undisturbed tap root.

Why Is It Better to Start Seeds as Transplants?

In real life, sometimes direct sown seeds just don't work out though. Certain environmental factors can inhibit the development of direct sown seeds. Cold weather hinders seeds such as corn or beans from germinating. But starting seeds indoors eliminates this issue. Have you found young emerging seedlings that were destroyed by pill bugs or other pests? A larger, established seedling is more likely to survive unaffected. Sometimes a limited growing season can be a good reason to break the rules on direct sown varieties. To deal with short Summers, starting watermelons indoors might be the best way to ensure that they ripen before the Fall frost. Starting transplants also facilitates succession planting allowing you to get a second harvest from a single location.

Succession Crop of Mung Bean Transplants Growing in Garlic Bed
By starting these mung beans in seedling trays they were ready to replace my garlic once it was harvested.

Can You Start Bean Seeds Indoors?

I love the convenience of directly sowing bean seeds in the ground. Every time I try it though, I end up getting burned. Before the first set of leaves has even emerged from the soil, my bean seedlings get attacked by pill bugs. Once the plant finally pops up, it looks mangled and is clearly stressed. Plant stress further attracts pill bugs and before I know it I'm trying to start a second batch of seeds. It's so frustrating!

The situation is completely avoidable. Recently I've resorted to starting my bean seedling indoors where they are totally protected. I just use a basic potting mix and put them in 2 inch square cell packs that are 2 1/2 inches deep. I don't let them get very big. As soon as the first set of leaves has fully emerged, I transplant them out into the garden. It's a little extra work, but I don't need many plants and I enjoy a 100% survival rate!

Pole Bean Plants Started Indoors Large Bean Harvest
These eight pole bean plants grew extremely well after being started indoors as transplants.

Can You Start Carrot Seeds Indoors?

Carrots are notorious for being slow germinators. To improve results, you can soak them for an hour before direct sowing. Or you could try transplants. Because the harvested part of a carrot plant is its root, any deformity in root structure can impact your yield. As shown in this video, you can start carrots in containers before transplanting. But the results might be less than perfect. For best results, you would either need an extremely long seedling container or you would need to transplant them outside while they are very young. In the future, I intend to pop them into the ground while they are very small, no taller than 1 inch.

Video: Danver Carrots Started Indoors
in Cone-tainers (Ray Leach Tubes)

Although they're less than perfect, these carrots were started indoors as transplants!

Can You Start Corn Seeds Indoors?

Corn requires warm soil during its germination period to ensure proper emergence. Some varieties need 100 days or more before reaching maturity. If your growing season is too short, then it might be worth starting your corn indoors to reduce time until harvest. A 4" deep pot can accommodate plants that are up to 3 weeks old before they finally need transplanted outdoors.

When direct sowing, be sure that your outdoor soil temperatures are at least 50° F or warmer. Otherwise, it's better to just wait. Failure to do so can cause inconsistent germination which impairs pollination and cob size. If you simply want to speed up germination time, you could try soaking the corn seeds overnight in 70° F water before planting. Some sweet corn varieties mature rather quickly and it might be worth trying them out if season length is the issue.

Tips For Transplanting Success

I prefer to start all of my seedlings myself, rather than buying them from a garden center. This is especially true of plants that don't take to transplanting. By starting them myself, I'm able to control how they are grown and the way their roots develop. In particular, the key to starting problematic seeds indoors lies in optimizing two vital factors: 1) Pot Size and 2) Time Until Transplant.

CONTAINER SIZE: Root vegetables such as carrots and beets will develop a long taproot. Planting the seeds in deep containers allows the roots to develop without interruption. Plants like watermelons and squash work well in wider, deeper pots. There is less root circling and a more natural development of the rooting structure.

SEEDLING SIZE: The other crucial element for success involves knowing when to put those seedlings out into the ground. We might be used to a 6 or 8 week old seedling. This works well for peppers and tomatoes, giving them a great head start. But corn, beans, squash and melons develop very quickly in the summer heat. Try planting them out when they are 2 weeks old. They won't even know that they were started in a pot. And once they're out in the ground, the roots will stretch and develop naturally, without stunting your plant's growth.

The bottom line: We don't always have the ideal circumstances for growing our plants. To ensure the best success, we may need to start some things in containers. As long as it works, who cares?

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