Direct Seed or Transplant?
Here in northern CA, the heat has arrived. It feels like we've gone from winter to summer in just the past few weeks and planting season is on!
Do you prefer to start seeds in trays or direct sow? This can be confusing for gardeners just getting started. Heck, it can even be confusing for experienced green thumbs. 15+ years later I still go back and forth depending on the year, weather and my mood.
To direct sow or not has a lot to do with personal preference. Am I feeling carefree and footloose? Then I direct sow.
I love the feeling of opening up a bed in my garden, digging a shallow trench and scattering seeds. There is an element of uncertainty that comes with direct sowing seeds.
Will they get enough water? Will the birds eat them? Will the weeds out compete them?
These are all good questions. It can be much harder to control the outcome in the wilds of the garden than in trays carefully tended in a greenhouse. For these reasons I also tend to start a lot of seeds in trays and then transplant.
BUT, and this is big, plants love to grow where they are sown. Direct sown plants have the chance for their roots to go deep and not be disturbed by transplant. So before you rush to the greenhouse, consider that if you can, you should direct sow some crops.
For us in zone 9 at 2500 ft elevation it is safe to plant frost tender annuals near the end of May. In 2021 I pushed this and planted some tomatoes and squash outdoors in early May only to be frosted on May 20th. In the end many of the plants lived but were severely stunted.
Squash, cucumbers and melons- These can be started in trays but often folks start them WAY too early in trays and end up with stunted plants. Species in this family don’t like their roots overly disturbed so if you can direct sow them, do it. Wait for the soil to warm before planting these or the seed can, and will, rot in the ground. Generally you want the soil to be above 70 F. All chance of frost should be past and t-shirt weather here to stay.
If you do start these in trays, only start them about 2-3 weeks before you intend to plant them!
Corn and Sunflowers- I put these two together because they can be started in trays very successfully but are also vigorous germinators when direct sown. They need to have adequate spacing so when direct sowing there are two choices.
1. If you are short on seed, sow the seed at finally spacings.
2. If you have enough seed, sow more thickly, about 3 per bed ft. Then thin to your strongest seedling and ideal spacing.
Beans- These do best direct sown along the same time as the above crops. The root is the first to develop, followed by leaves pushing through the soil.
I have also sown beans in trays and transplanted successfully. Just be sure to transplant as quickly as possible and only start them about 2 weeks before your anticipated planting date.
Other crops that traditionally do best direct seeded are the roots including carrots, beets and turnips. It is possible to transplant these but care must be taken to not injure the root in the process. Transplanted carrots often result in twisted roots.
Culinary herbs: Basil, cilantro, dill and parsley- I generally sow these in trays then transplant. The small seeds can easily get lost in the garden so I find it is a better use of my seed to get them exactly where I want through transplanting. The exception is cilantro. Because I have a lot of seed, I tend to direct sow cilantro in a shallow trench densely planted.
Another note about cilantro: When sown now, it will bolt to seed fairly quickly due to the heat. You can and should harvest the seeds to replant in the fall. Cilantro will grow all winter in zones 9/10. If you must have fresh cilantro in your summer salsa then you will need to sow it in succession throughout the summer.
I'll be back next weekend with more info about planning ahead for the heat in your garden.