Start seeds inside: Wait till April for tomatoes & peppers, but go ahead with cool-weather vegetables

Photo by Connie Oswald Stofko

by Connie Oswald Stofko

Readers have been asking me whether they can start seeds inside now.

It’s still too early to start seeds for tender plants such as tomatoes, peppers and cucumbers, said Mark Yadon, vice president at Mischler’s Florist and Greenhouses, 118 South Forest Rd., Williamsville. More details are below.

But if you want to plant seeds indoors now, try cool-weather vegetables, such as broccoli, cauliflower and lettuces. Again, we’ll give you more details.

Why starting your seeds too early is worse than starting too late

Each plant has a set number of days from germination of the seed to the time it produces fruit, but “If you try to cheat by starting your seeds a month early, it doesn’t always work,” Yadon said.

When you start your seeds too early, Yadon explained, your seedlings don’t get enough light (unless you have artificial plant lights). When the seedling doesn’t have enough light, it stretches to to reach for the light. The plant becomes leggy and weak.

If you try to give your seedlings more light by putting them outside too early, the weather may be too cold and there might be a frost. Then you’d have to somehow protect your seedlings from the weather.

“It’s easier and less stressful to just wait” and plant seeds at the appropriate time, he said.

Know when to expect the last frost

Your tender plants such as tomatoes, peppers and cucumbers can’t be planted outside until the danger of frost has passed. To make sure your seedlings are ready at the right time– and not sooner– it helps to know when to expect the last frost in your area.

As a rule of thumb, many Western New Yorkers use Memorial Day as their target, but the average date of the last frost in Western New York can range from the end of April for spots on Lake Ontario to the end of May or beginning of June in some Southern Tier areas. See a map of average last spring frosts here.

Also note that microclimates will affect how soon you can plant seedlings outside. For example, you might be able to plant sooner in a sunny, protected area up against a house.

Bonus tip: That map for last spring frost shows the average date. The last frost could happen earlier or later. Here’s a tip from Yadon to ensure you have seedlings ready when the weather is ready.

“Don’t put all your seeds in one basket,” Yadon said.

Information on the packet will tell you how many weeks before planting outside you should start your seeds inside. Determine the date you should plant your seeds. Plant some seeds the week before that date, some seeds the week of that date and some seeds the week after that date.

If the last frost is earlier than average, you can plant your first set of seedlings outside. If the last frost comes on the average date, you can plant your second set of seedlings. If the last frost is late, you still have some strong seedlings that are ready at the proper time.

Yadon said we gardeners shouldn’t be afraid to throw away some seedlings. He knows it seems wasteful, but it’s more wasteful to try to care for more plants than you have room for or have time for. And if the seedlings are weak, they’re not going to do well.

Lyn Chimera, a Master Gardener with Cornell Cooperative Extension in Erie County, suggests this factsheet with more tips on starting seeds.

Seeds and containers

At Mischler’s, you can buy Renee’s Garden seeds, which include some heirloom varieties of vegetables and organic seeds. You can also buy seed-starting kits, which make planting seeds a little easier. They’re fun for kids, too.

If you use your own containers for starting seeds, don’t use a container that’s too large, Yadon said. If the soil is consistently wet, it can promote disease. Using smaller containers helps the soil dry out in between waterings, which is good for the plant.

For tomatoes, Yadon recommends not using anything bigger than a K-Cup, those small plastic cups that hold coffee grounds for Keurig coffee makers. In fact, used K-Cups are great for starting seeds, he said, because they have drainage holes in the bottom. Just clean them out before using. Ask your friends and co-workers to start saving them now and you will have plenty by the time you’re ready to start planting.

Tomatoes, peppers, cucumbers and squash

To have seedlings that you can plant outside in the middle of May, you can start seeds for tomatoes and peppers around the first week of April, Yadon said. Again, check the average last frost for your area.

The staff at Mischler’s hasn’t started their tomato seeds yet, and they have better control over the growing conditions in their greenhouses than you have in your house, Yadon noted. They will plant some tomato seeds on March 28, but most won’t be started until April 7. Don’t start your seeds too early.

You can plant cucumber and squash seeds even later because they take less time to germinate and grow fast, he said. Start those seeds around April 30.

For other tender vegetables, check the seed packet. It will tell you how many weeks before the last frost to start seeds indoors.

Cool-weather vegetables

There are some vegetables that like cooler temperatures and can take a little frost. You can start these seeds indoors now:

  • Broccoli
  • Cabbage
  • Cauliflower
  • Swiss chard
  • Peas
  • Spinach
  • Any lettuces

Radishes are cool-weather vegetables, too, but it’s better if you directly sow them outside rather than starting them indoors, Yadon said.

You can plant your seedlings outside around the middle to the end of April, but when you plant depends a lot on the weather, he said.

You first need to harden off your seedlings to acclimate them to the cooler outdoor temperatures. You do this by having them outside (either in their containers or planted in a garden bed) for four or five days in temperatures that are cool (40 degrees Fahrenheit) but not freezing. Watch the five-day forecast to see if there will be a string of days when even the overnight temperatures aren’t freezing.

Once your plants are hardened off, they can take frost, he said.

You also have to make sure the soil can be worked. In 2014, the soil was still frozen in April and we couldn’t plant anything outside. In other years, it has been too wet to plant in mid-April. If you scoop up a handful of soil and it clumps, it’s too wet. If you can break it apart, it’s ready to be worked.

With lettuce, you could work around some of these temperature and soil issues by planting in a decorative container. You can plant up the container even if the soil in your garden is too wet to work. And you can have your plants outside in the container when temperatures are cool, but bring it in if the lettuce hasn’t been hardened off and there is the danger of frost.

Get more details on growing cool weather vegetables in this article. 













6 Comments on “Start seeds inside: Wait till April for tomatoes & peppers, but go ahead with cool-weather vegetables

  1. Hi Patricia, what does it say on the seed package? How long will it take from the time the seedlings are in the ground until you get a crop? Plus, it probably takes six weeks for the plants to grow to seedlings. I’m guessing it’s a bit late to start from seeds now, but you can check with the Master Gardeners in your county. Maybe they can give you a happier answer. I hope that helps.

  2. Something ate my pepper seedlings! Is it too late now (May 31) to start them from seed now all over again?

  3. Lorraine, most seed packets have planting information on them, and you can follow those directions. Some seeds, such as radish seeds, are planted directly into the ground outside; you don’t start them inside and transplant them. It seems that is what you do for beets, too. Here is information I found on the site of a seed company for beets: Sow beet seeds in well-worked, well-drained soil in full sun after danger of frost in spring. I hope that helps!

  4. I believe I planted my BEET seeds (in the house) too early. They did
    not germinate yet tho. How soon or how late to plant BEET seeds?
    A NOVICE in learning.

Leave a Reply

Your email address will not be published. Required fields are marked *

Name *