Starting Seedlings Indoors in Summer

LIKE SHOPPING FOR HOLIDAY PRESENTS in July, it’s a little difficult to get in the mood to start seedlings in the middle of summer. That’s because, for many gardeners, starting seedlings indoors has become ingrained as a late winter or early spring activity. But for certain vegetables, a summer batch of seedlings is a great idea because it can reward you with a second crop of cool weather vegetables that otherwise wouldn’t be possible.

Still, starting seedlings in the summer is not a common practice. Most backyard gardeners wouldn’t even consider the idea. It’s just too much work. You may already be thinking to yourself that this is a goofy idea. But if you’re interested in getting more from your garden, you’ll want to suspend your disbelief for a minute to consider the idea.

Why are summer seedlings a good idea?

In the same way that starting seedlings indoors in the spring helps you get a head start on the warm growing season, starting seedlings in summer can help you get a jump on the fall growing season. So for many of the short time-to-maturity vegetables and herbs that you would consider starting indoors in spring – for example, scallions, broccoli, Brussels sprouts and dill – you can also start them indoors in summer for a late fall harvest.

Here are four reasons why this is a good idea:

Broccoli Seedlings

You could start a late crop of broccoli seedlings for harvest in the fall. (Credit: Lauren Pressley)

1. Air conditioning helps plants germinate. In the heat of summer, it’s too hot for certain cool weather vegetables to sprout in the garden. But it’s cool and shady inside your house, and the conditions are just right.

2. No heating pad needed. It’s warm enough that you don’t need a heating pad to facilitate germination.

3. Sunlight is readily available. You don’t need grow lights. Just make sure there’s not too much sun and the seedlings don’t dry out.

4. Avoid the normal pests. By the time the summer seedlings are transplanted, the normal cycle of pests has often run its course. For example, I wait until July to plant zucchini seedlings outside to avoid squash borer.

Sometimes it’s better to sow directly

With certain vegetables like lettuce, arugula, carrots and radishes, you’ll have better luck if you sow them directly into the garden. But for others that don’t mind being transplanted, you can start a few weeks earlier. The important point to consider is that most areas with cold winters have only a limited number of days between the start of cooler temperatures and the first hard frost. Sometimes the window is too short.

On the other hand, certain vegetables take too long to mature even if you start them indoors. You wouldn’t want to start a late summer crop of eggplant or tomatoes, for example, because they would never ripen in time.

Tomato Seedlings

Tomatoes would NOT be a good choice for summer seedlings.

Do you have the gumption?

Of course, starting seedlings takes a lot of time and attention. If you’re like me, and make up your own paper pots, there’s a lot of work involved (even if there’s not much cost). Many backyard gardeners won’t have the gumption to start a second batch when the pleasures of summer beckon. But there are times when “life events” prevent you from starting seedlings in the spring. It’s nice to know you still have the option to start fresh in the summer.

I started seedlings this year in March, but wish I had done more. I’m going to start a second batch for the fall now, rather than direct sow and battle the hot, dry weather. I’ll let you know how it turns out.

Have you ever started seedlings indoors during the summer. How did it turn out? What strategies did you use to combat the heat?

Related articles that might interest you:

1. Transplanting Seedlings Outdoors
2. When to Start Seedlings Indoors
3. Don’t Use Compost Tea on Seedlings
4. My Plan for Seed Starting Mix



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6 Responses to “Starting Seedlings Indoors in Summer”

  1. July 17, 2012 at 3:57 pm #

    Great post! Reminds me it is time to start seeds for my fall garden!

    • July 17, 2012 at 7:47 pm #

      Glad it was helpful. Hope your fall garden goes well.

  2. July 18, 2012 at 8:27 pm #

    Bill I definitely would like to know how it goes as I started many fall harvest seeds recently due to our very short season.

    • July 18, 2012 at 10:53 pm #

      Thanks Donna — I’ll let you know how it goes.

  3. Monica
    July 21, 2012 at 1:00 am #

    Hi Bill,
    Starting your own seeds is an inexpensive way to create your own plants, but only if you need them. So, if you want only two tomato plants, don’t plant an entire pack (unless you have a friend to share them with).

    • July 21, 2012 at 8:15 am #

      Heirloom seedlings also make a great gift. People really enjoy it when you give them something they’ve never grown before.

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