Mustard Greens in Zone 10B — Florida

Mustard greens bring a zesty kick to your Florida garden and kitchen. Their peppery bite adds depth to salads, stir-fries, and braised dishes. Plus, growing your own means you get to harvest them at their peak, avoiding the wilted, pre-packaged stuff at the store.

Florida gardening calendar is different, and while summer is the slow season, Mustard Greens thrive in our cooler months. With our long growing season, you can easily squeeze in a crop of these flavorful greens. Just keep an eye on the weather and you'll be enjoying fresh mustard greens in no time.

Starting mustard greens indoors gives you a head start, but honestly, direct sowing is usually easier here in Florida. If you want to get a jump on the season, though, start seeds indoors from late November through mid December, about 3 weeks before you plan to transplant. Use seed trays with a good seed-starting mix, provide warmth (a heat mat helps), and ensure they get plenty of light – a grow light is ideal.

Bottom watering is key to prevent damping off. This is when you set the tray in a shallow container of water, allowing the soil to absorb moisture from the bottom. Remember, our spring character is reversed, so you're actually starting these when much of the country is winding down.

Transplant your mustard greens seedlings outdoors from late December through early February. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. This prevents shock.

Space the seedlings 6-12 inches apart in well-drained soil. Keep an eye on the forecast; those occasional cold snaps can still hit us. If a freeze is predicted, cover your seedlings with frost cloth to protect them.

Direct sowing is a simple and effective method for growing mustard greens in Florida. Sow seeds directly into the garden from early December through early November. Prepare the soil by loosening it and amending with compost.

Make shallow furrows, sow seeds 6-12 inches apart, and lightly cover with soil. Keep the soil consistently moist until germination. Direct sowing eliminates the risk of transplant shock and allows the plants to develop strong root systems.

Mustard greens need consistent moisture, especially in our sandy Florida soil. Aim to keep the soil evenly moist, but not waterlogged. In general, during our drier fall and winter months, you'll likely need to water 1-2 times per week.

Stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Give them about 1 inch of water per week, either from rainfall or irrigation.

Water at the base of the plants to avoid wetting the leaves, which can encourage fungal diseases in our humid climate. Overwatering can lead to root rot, while underwatering can cause the leaves to become tough and bitter, and trigger premature bolting. Add a layer of mulch, like pine straw or wood chips, to help retain moisture and suppress weeds.

You can expect your first harvest of mustard greens from late to early January. Mustard greens are ready to harvest about 45 days after planting. Young leaves have a milder flavor, while larger leaves are spicier.

Harvest leaves as needed by snipping them off at the base of the plant. This allows the plant to continue producing new leaves. To encourage continued production, remove any flower stalks that appear.

As our first frost approaches in late December, harvest any remaining leaves, even if they're small. You can also cover the plants with frost cloth to extend the harvest a bit longer.

Mustard greens can face a few challenges in Florida, but with a little attention, you can keep them healthy and productive. Here's what to watch out for:

Flea Beetles

• What it looks like: Tiny round holes (shot-hole pattern) in leaves. You'll see small dark beetles that jump when disturbed. They cause the most damage to young seedlings.
• What causes it: These small jumping beetles feed on the leaves, especially when plants are young and vulnerable.
• How to fix/prevent it: Protect seedlings with row covers. You can also delay planting until plants are larger and more resilient. Try coating the leaves with kaolin clay or spraying with neem oil. Interplanting with basil or catnip can also help deter them.

Aphids

• What it looks like: Clusters of tiny soft-bodied insects (green, black, or white) on stems and leaf undersides. You might notice a sticky honeydew residue and curled or distorted new growth.
• What causes it: These sap-sucking insects reproduce rapidly, especially in warm weather. Ant colonies may even farm them for their honeydew.
• How to fix/prevent it: Knock them off with a strong spray of water. Encourage natural predators like ladybugs and lacewings. For heavy infestations, use insecticidal soap or neem oil. Avoid excess nitrogen fertilizer, as it attracts them.

Cabbage Worms

• What it looks like: Smooth green caterpillars on the leaves. You'll see irregular holes chewed in the leaves, dark green droppings, and white butterflies fluttering around your plants.
• What causes it: These are the larvae of white cabbage butterflies. They can have multiple generations per season in our warm climate.
• How to fix/prevent it: Bt spray is very effective. Use floating row covers to prevent the butterflies from laying eggs. You can also handpick the caterpillars. Interplant with aromatic herbs like thyme and sage to deter them.

Bolting in Heat

• What it looks like: The plant sends up a flower stalk. The leaves become tough and bitter, and the harvest quality declines.
• What causes it: Mustard greens are a cool-season crop and will bolt when temperatures rise.
• How to fix/prevent it: Time your plantings for the cooler months. Choose bolt-resistant varieties. Provide shade during warm spells. Mulch to keep the soil cool. Harvest before bolting progresses.

Florida Specific Challenges: Our hot heat and very-high humidity create ideal conditions for fungal diseases. Be sure to provide good air circulation and avoid overhead watering to minimize these problems. Keep a close eye on your plants, especially during the wet-summer months, and address any issues promptly to keep your mustard greens thriving.

Mustard greens play well with certain neighbors in the garden. Onions and garlic are great companions because their strong scent deters pests. Beets are also good companions, as they don't compete for the same nutrients. Dill attracts beneficial insects that prey on pests. Lettuce provides ground cover and helps retain moisture.

Avoid planting mustard greens near strawberries and tomatoes. Strawberries and brassicas can inhibit each other's growth. Tomatoes are susceptible to similar pests and diseases as mustard greens, potentially leading to increased problems.