Sweet Alyssum in Zone 8B — Florida

Sweet Alyssum is a fantastic addition to any Florida garden. It's not grown for eating, but for its sweet fragrance and delicate beauty. It makes an excellent ground cover, spilling over containers, and attracting beneficial insects that help with pollination and pest control in your vegetable garden. Plus, it flowers almost year-round here!

Our Florida gardening calendar is different, and summer is the slow season for many crops. But don't worry – by planting Sweet Alyssum at the right time, you can enjoy its beauty and benefits for most of our 303-day growing season. We'll navigate the humidity and brief cooler periods together.

Starting Sweet Alyssum indoors is an option, but honestly, direct sowing is often easier here in Florida. However, if you want a head start, especially for early spring blooms, it's worth considering.

Begin in mid December through early January, about six weeks before you plan to transplant. Use seed trays with a good seed-starting mix and keep them in a warm location with plenty of light, either natural or from grow lights. Bottom watering is a great way to keep the soil moist without overwatering and risking fungal issues in our humid climate. Remember, spring here is reversed compared to other regions!

Transplant your Sweet Alyssum seedlings outdoors in early February through mid March. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sun and wind, preventing transplant shock.

Space them 6-8 inches apart to allow for their spreading growth habit. Keep an eye on the weather – a late cold snap can happen, so be prepared to cover your young plants if needed. Our weather can be unpredictable, but that’s Florida gardening!

Direct sowing Sweet Alyssum is simple and effective in our climate. You can sow seeds directly into the garden from early February through mid October, giving you a long window of opportunity.

Prepare the soil by loosening it and adding some compost. Sweet Alyssum isn't too picky, but well-draining soil is always best, especially with our high humidity. Gently press the seeds into the soil and keep them consistently moist until they germinate. Thin seedlings to 6-8 inches apart. Direct sowing is a great low-effort way to get these beauties established.

Sweet Alyssum needs moderate watering to thrive, but it's crucial to get it right in Florida's unique climate. While it's not drought-tolerant, it also doesn't like soggy conditions, which can lead to fungal problems, especially with our extreme humidity.

During the cooler months (fall, winter, and early spring), water deeply about once a week, or when the top two inches of soil feel dry to the touch – use the "finger test". In the wet-summer, you might not need to water at all, unless we're experiencing a dry spell. Avoid overhead watering to minimize the risk of fungal diseases. Instead, water at the base of the plants.

During the hottest part of summer, Sweet Alyssum may go dormant, but it usually bounces back when temperatures cool down. Watch for signs of overwatering (yellowing leaves) or underwatering (wilting). Aim for about 1 inch of water per week, adjusting based on rainfall. A layer of mulch around the plants helps retain moisture and suppress weeds, but don't overdo it – airflow is important here!

Sweet Alyssum requires minimal pruning, but a little maintenance helps keep it looking its best. The main thing is to shear back the plants by about half when they start to get leggy, usually in midsummer when the heat is intense. This encourages fresh growth and more blooms.

Don't be afraid to cut them back hard – they're pretty resilient. As the first frost approaches around mid- December, you can leave the plants in place. They may die back a bit, but they often return in the spring.

Since Sweet Alyssum is primarily grown for its ornamental value and as a beneficial insect attractant, there's no need to "harvest" in the traditional sense. The plants flower continuously from mid March through late December, providing a beautiful display and attracting pollinators to your garden.

The continuous flowering also means you're continuously benefiting from its role as living mulch and a haven for beneficial insects. Simply enjoy the beauty and benefits it brings to your garden! As the first frost approaches, you can leave the plants in place; they may self-seed, giving you a new crop in the spring.

Even though Sweet Alyssum is relatively easy to grow, you might encounter a few problems here in Florida. Here are the most common ones:

Downy Mildew

• What it looks like: Yellow patches on the upper side of the leaves, with a fuzzy gray-purple growth on the undersides. Leaves will eventually turn brown and die, starting from the bottom of the plant.
• What causes it: This is caused by an oomycete pathogen that thrives in cool, humid conditions. The spores are spread by wind.
• How to fix/prevent it: Remove any affected leaves immediately to prevent the spread. Improve air circulation around the plants. Always water at the base, avoiding overhead watering. Consider using a copper-based fungicide as a preventative measure. Look for resistant varieties when purchasing seeds.

May Die Back in Extreme Heat

• What it looks like: The plant may stop flowering, and the foliage can look stressed or even die back during the hottest part of the summer.
• What causes it: Our intense summer heat can be too much for Sweet Alyssum, causing it to go dormant.
• How to fix/prevent it: Provide some afternoon shade during the hottest months. Shear back the plants to encourage new growth once temperatures cool down. Ensure adequate watering, but avoid overwatering in our humid environment.

Flea Beetles

• What it looks like: Tiny, round holes (shot-hole pattern) in the leaves. You might also see small, dark beetles that jump when disturbed.
• What causes it: These are small jumping beetles that feed on the leaves. They are most damaging to young seedlings.
• How to fix/prevent it: Use row covers to protect seedlings during their vulnerable stage. Delay planting until the plants are larger and more resilient. Apply kaolin clay to the foliage. Neem oil spray can also help. Interplant with basil or catnip to deter them.

Florida-Specific Challenges: The hot heat, very-high humidity, and wet-summer rainfall create an environment where fungal diseases can quickly spread. Proper watering techniques, good air circulation, and choosing the right planting time are essential for success with Sweet Alyssum in our unique climate.

Sweet Alyssum makes a great companion plant in the Florida garden. Plant it near broccoli to attract beneficial insects that prey on broccoli pests. It also works well with potato, attracting hoverflies whose larvae eat aphids that might attack your potato plants.

Sweet Alyssum is great planted near lettuce. It acts as a living mulch, keeping the soil cool and moist, while attracting pollinators to your lettuce if it bolts. There aren't any specific plants to avoid, but generally, don't plant it so densely that it restricts airflow around other plants, as this can increase the risk of fungal diseases in our humid climate.