Sun Gold Tomato in Zone 5B — Mid-Atlantic

Sun Gold tomatoes are worth their weight in gold here in Zone 5B. Their intense sweetness and practically addictive flavor makes them the perfect snack straight from the vine, adding a burst of sunshine to salads, or even roasting for a decadent sauce. Plus, they thrive in our warm, humid summers, rewarding you with a truly prolific harvest.

We Mid-Atlantic gardeners know we have to be ready for anything, from unexpected temperature swings in spring to the inevitable humidity. But with a little planning and attention to timing, you can easily enjoy a bumper crop of Sun Golds within our 178-day growing season.

Starting your Sun Gold tomato seeds indoors is the way to go in our region, giving them a head start against our variable spring weather. Aim to sow your seeds indoors from mid-March through early April, about six weeks before you plan to transplant them outside. This timing takes advantage of our moderate spring, allowing seedlings to grow strong without facing late frosts.

Use seed trays or small pots filled with a good seed-starting mix. Keep the soil consistently moist (but not soggy) by watering from the bottom to encourage strong root growth and prevent damping off. Provide warmth with a heat mat and plenty of bright light – a grow light works wonders – until they're ready for transplanting.

Transplant your Sun Gold tomato seedlings outdoors anytime from early May through early June, once the danger of frost has passed. Before you move them permanently, be sure to harden them off. This means gradually exposing them to outdoor conditions for about a week, starting with just a few hours each day.

Plant them 24-36 inches apart in a sunny spot with well-drained soil. Keep an eye on the weather forecast, especially early on. We sometimes get unexpected cold snaps even in May. Be ready to cover your young plants if a late frost threatens.

Sun Golds are thirsty plants, and consistent watering is key to preventing cracking and maximizing your harvest, especially in our humid Mid-Atlantic summers. Because they are not drought tolerant, these plants need regular watering, and the prolific production demands consistent moisture. Aim to give them about 1-2 inches of water per week, either from rainfall or irrigation.

Check the soil moisture by sticking your finger about 2 inches deep. If it feels dry, it's time to water. Water deeply at the base of the plant, rather than overhead. This helps to prevent fungal diseases that thrive in our humid climate.

Signs of underwatering include wilting leaves and blossom end rot. Overwatering can lead to yellowing leaves and root rot. A good layer of mulch around the base of the plants helps retain moisture and keeps the soil temperature even, reducing the risk of cracking.

Sun Gold tomatoes are vigorous indeterminate growers, so they absolutely need strong support to keep them off the ground and prevent them from sprawling. Given how aggressively they grow, these need tall, strong support. Cages or sturdy stakes work well, but make sure they are tall and strong enough to handle the weight of the mature plant and its abundant fruit.

Install your chosen support at planting time to avoid damaging the roots later. As the plant grows, gently tie the main stem to the stake or weave it through the cage to keep it upright. This will improve air circulation, reduce disease, and make harvesting easier.

Pruning is essential for managing the rampant growth of Sun Gold tomatoes and maximizing fruit production. If you don't prune them, they will take over the garden! Focus on removing suckers, which are the small shoots that grow in the "V" between the main stem and the branches.

Prune suckers regularly throughout the growing season, especially early in the morning when the plant is less stressed. In late summer, you can also top the plant (cut off the top of the main stem) to encourage the remaining fruit to ripen before our first frost arrives around mid-October.

Get ready for a non-stop harvest of sweet, golden goodness starting sometime in late June through mid-August! Sun Golds are ready to pick when they turn a vibrant orange-gold color, feel slightly soft to the touch, and practically fall off the vine. They are intensely sweet at this stage.

Gently twist or snip the ripe tomatoes from the plant, being careful not to damage the surrounding fruit or stems. The more you harvest, the more the plant will produce. As the end of the season approaches and frost threatens, harvest any remaining green tomatoes and bring them indoors to ripen.

Here are three common problems Mid-Atlantic gardeners might face with Sun Gold tomatoes:

Cracking

• What it looks like: Splits in the tomato skin, either concentric circles around the stem or radial lines radiating from the stem.
• What causes it: Inconsistent watering, especially heavy watering or rain after a dry spell. The fruit absorbs water faster than the skin can expand.
• How to fix/prevent it: Water consistently, mulch to maintain even moisture, and harvest promptly when ripe.

Over-Production

• What it looks like: A huge number of tomatoes all at once.
• What causes it: They are just naturally productive.
• How to fix/prevent it: Harvest frequently and share with neighbors.

Early Blight

• What it looks like: Brown spots with concentric rings (target or bullseye pattern) on lower leaves, spreading upward. Leaves yellow and drop.
• What causes it: Fungal disease (Alternaria solani) that thrives in warm, humid conditions and spreads via soil splash.
• How to fix/prevent it: Remove and destroy affected leaves, mulch to prevent soil splash, water at the base, improve air circulation through spacing and pruning, and rotate crops yearly.

Mid-Atlantic Specific Challenges: Our moderate-to-hot summers, combined with high humidity and even rainfall, create ideal conditions for fungal diseases like early blight. Consistent watering is crucial to prevent cracking, but you have to be careful not to overwater in our already humid climate.

Companion planting can help your Sun Gold tomatoes thrive. Basil is a great companion because it repels tomato hornworms and other pests. Carrots and parsley attract beneficial insects that prey on tomato pests. French marigolds deter nematodes and other soil-borne pests.

Avoid planting tomatoes near brassicas (like cabbage and broccoli) because they compete for nutrients. Also, fennel inhibits tomato growth, and corn can attract tomato pests.