Dig It: Your Vegetable Gardening Questions, Answered

Laura asked: When should I start seeds for fall plants?

Now is the time to start seeds for fall crops that need a longer time to produce, like broccoli, cauliflower, cabbage, and Brussels sprouts. You can start those indoors and then transition them outdoors when temperatures start to drop to the 60s and 70s.

You can wait a few weeks to start crops that don’t take as long to mature, and sow those directly outside. These include roots like beets, turnips, radishes, and carrots, as well as greens like kale, collards, lettuce, and arugula.

Serena asked: How do you prune tomatoes?

Pruning tomatoes isn’t always necessary, but it can increase your harvest. Pruning only needs to be done on indeterminate tomato varieties. Indeterminate tomatoes have a main stem that continues growing from the top like a vine. You can look at plant tags or seed packets to know whether or not your tomatoes are indeterminate.

When pruning tomatoes, the goal is to remove a third tier of stems called suckers that grow between the main stem and the side stems. These can take energy away from the plant. You can remove suckers with your fingers when they’re small. If they’re larger, you may need to use hand pruners.

It’s very important to use clean pruners when trimming tomatoes so you don’t transfer any diseases from plant to plant. Really conscientious gardeners will carry around a solution of water and bleach and sterilize their pruners between plants. Really, for many tasks in the garden, it’s important to keep your garden tools clean and sharpened. It only takes a few minutes and some basic materials to get your tools in shape.

Robin asked: Can you plant potatoes with tomato plants? I heard it causes potato blight – is that true?

Tomatoes and potatoes are in the same plant family, called the Nightshade Family. Eggplant and peppers are also in this family. Crops of the same plant family often battle the same diseases, so it’s usually best not to plant them all near one another. This includes potatoes and tomatoes, which both can get the disease called ‘late blight.’ You can grow both tomatoes and potatoes in your garden, but spread them out. Also, rotate Nightshade Family crops around your garden, growing them in different spots each year.

You can also prevent blight by watering tomato plants at the base, not getting the leaves wet; planting your tomatoes far enough apart that there’s good airflow; and planting varieties known to be blight resistant. One fun heirloom variety that’s blight resistant is called Mr. Stripey, pictured here — weighing in around one to two pounds at maturity, it's a beefsteak-type tomato with pinkish-red and yellow streaks, and a high sugar content that makes them sweet and delicious. The indeterminate vines start bearing in about 80 days and reach 8 to 10 feet tall.