Nightshades (Solanaceae)
Nightshade vegetables belong to the Solanaceae family, which includes a wide variety of plants, some of which are commonly grown as food crops. The name “nightshade” is thought to have originated from the fact that some of these plants can be toxic or have medicinal properties. The family includes both edible and poisonous species, so not all nightshades are safe for consumption. However, those we commonly grow in our garden have safe fruits after they ripen.
The nightshade family boasts a diverse range of vegetables, including the familiar tomatoes, potatoes, peppers, eggplants, and goji berries.
When choosing the right variety for each nightshade, think about the purpose. For example, there are many varieties of tomatoes; each type is suitable for different ways of consumption. Some types of tomatoes are best eaten fresh in a salad, while others are ideal for sauce or dried. This applies to all nighshades. Usually, this information is written on the seed’s label, or when buying seedlings, a garden center employee will give you this information.
Planting and harvesting nightshades
Nightshades, like tomatoes, peppers, and eggplants, are propagated using seeds from ripe fruits. After collecting the seeds, let them dry completely and store them in a cool, dry place until the next planting season. Rather than sowing these seeds directly into garden beds, start them in a greenhouse or warm, sunny environment. Direct planting in the soil could lead to poor growth conditions or expose young seedlings to pests.
For optimal growth, it’s essential to start sowing the seeds in a greenhouse early in spring, once the days warm up and there’s more sunlight. Insufficient sunlight can hinder seed germination, making winter sowing less successful. Once the plants reach about 12 cm in height, they can be transplanted into the garden. It’s important to ensure the weather is consistently warm enough, as nightshades don’t thrive in cold conditions.
If you choose to save the seeds from your plants, make sure that the initial plants (or seeds) are not labeled “hybrid”, as those are not meant to be propagated but bought every year new.
Nightshade plants thrive in well-drained soil with a slightly acidic to neutral pH. They also benefit from soil rich in nitrogen, which supports their growth.
Potatoes
Potatoes are not grown from seeds as other nighshades, but from their tuber – potato. You can cut the potato into smaller pieces before planting to increase the number of potato plants from a single potato. Choose certified seed potatoes to avoid diseases. Avoid grocery store potatoes as they may be treated with growth inhibitors. Each piece of potato should have at least 1-2 “eyes,” which are tiny buds or sprouts. These eyes will grow into new plants.
Allow the cut pieces to sit in a cool, dry place for 1-2 days. This procedure helps the cut surfaces form a callus, reducing the risk of rot when planted. Once cured, plant each piece about 3-4 inches deep in soil, with the eyes facing up. Space them about 12 inches apart to give the plants room to grow. You can also try to grow potatoes from their peels.
Harvesting potatoes:
- For “new potatoes,” you can begin harvesting about two weeks after the plant starts flowering.
- For fully mature potatoes, wait until the plants’ foliage turns yellow and begins to die naturally, usually around 2–3 weeks after flowering. At this stage, the potatoes have reached their maximum size and can be cured for long-term storage.
Spacing and sunlight
Among all plant families, nightshades likely have the highest sunlight requirements, needing up to 8 hours of direct sunlight each day for proper growth and fruit development.
It’s important not to plant nightshades too close to each other – too much moisture leads to diseases and pests. Excess shade leads to the slow ripening of the fruit.
Watering
Although nightshades are often said to need heavy watering, my experience suggests otherwise. They require frequent watering during the seedling stage, but once transplanted and the plants start forming flowers and fruit, it’s better to reduce watering.
For example, tomatoes develop a more substantial flavor when they receive less water as the fruit ripens. I usually water grown tomatoes once every two to three days, the same with peppers and eggplants. I don’t water the potatoes because they are planted at the beginning of spring, when it usually rains enough.
Harvesting
Harvest fully ripened fruit – not green and not too soft. Overly ripened fruit won’t last long even in the fridge, and it unnecessarily takes away energy from the plant that it could devote to ripening and growing new fruits.
If it rains heavily, it is better to pluck unripe fruits (this applies to tomatoes and peppers), dry them thoroughly, and let them ripen in a sunny and dry place. If we don’t do this and it rains for several days, our fruits usually crack or rot and often don’t ripen afterward.
Companion Planting and Interplanting with Nightshades
It’s generally best to avoid planting different nightshade species together (such as potatoes and tomatoes) as they compete for the same nutrients and attract similar pests. However, tomatoes and peppers can be grown together without much issue, as they tolerate each other well.
For pest control and to improve the soil conditions, we can plant near them aromatic flowers and herbs such as nasturtium, basil, parsley, thyme, oregano, cilantro, sage, Sweet Alyssum, French Marigolds, chives, and garlic. Crimson clover can help with soil nitrogen and natural weed control.
Nightshades shouldn’t be planted near cucumbers, Brassicas, fennel, dill, Sweet corn, and rosemary.
Harvest times
Tomatoes: 60–100 days after transplanting (some varieties, like cherry tomatoes, mature faster, while larger varieties may take longer).
Peppers: 60–90 days after transplanting, depending on the variety (bell peppers tend to take longer, while hot peppers can mature more quickly).
Eggplants: 70–85 days after transplanting.
It takes 6 – 8 weeks to grow these nighshades from seed to ready-to-go seedling.
Potatoes generally take 70 to 120 days to be ready for harvest, depending on the variety and growing conditions. Here’s a breakdown of the timeline:
- Early-Season Varieties
- Days to Harvest: 70–90 days.
- Harvest Tips: These are often ready in late spring or early summer. They produce smaller potatoes and are typically harvested young, often as “new potatoes.”
- Mid-Season Varieties
- Days to Harvest: 90–110 days.
- Harvest Tips: Mid-season potatoes are harvested in midsummer, producing medium-sized tubers.
- Late-Season Varieties
- Days to Harvest: 110–120 days or more.
- Harvest Tips: These are harvested in late summer to early fall and are larger, often used for storage due to their longer shelf life.