Sun Gold Tomato in Zone 5B — Midwest

Sun Gold tomatoes are like sunshine in your mouth, and they're absolutely worth the effort in a Midwest garden. Their intense sweetness and early maturity make them a favorite, and they produce like crazy through our warm summers, offering handfuls of delicious snacks straight from the vine.

We know Midwest weather can be unpredictable, but Sun Golds are fast growers. With a little planning and attention to the timing, you can enjoy a bountiful harvest within our 168-day growing season, even with the occasional summer heat spells we get.

Starting Sun Gold tomatoes indoors is the way to go here. You have about a 3-week window from late March through mid April to get those seeds going, about 6 weeks before you'll want to transplant them outside. Use seed starting trays and a good seed starting mix.

A heat mat can help with germination, and once they sprout, make sure they have plenty of light – a grow light works wonders since our spring weather can be a bit gloomy. Don't forget to water from the bottom to encourage strong root growth; just set the tray in a shallow dish of water until the soil surface is moist.

Given our moderate-to-late springs, getting a head start indoors ensures you'll have ripe tomatoes before the first frost threatens.

Transplant your Sun Gold tomato seedlings outdoors anytime from early May through early June, once the danger of frost has passed. It's worth watching the 10-day forecast, since we sometimes get a late frost. Before planting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Plant them 24-36 inches apart in your fertile soil. This gives them room to sprawl, because they will get BIG. Be gentle when transplanting, and water them in well.

Sun Golds are thirsty plants, and consistent watering is key to preventing cracking and maximizing yield, especially during our moderate-to-hot summer heat spells. Aim to give them about 1-2 inches of water per week, depending on rainfall. Stick your finger about 2 inches deep into the soil; if it feels dry, it's time to water.

Water at the base of the plant to avoid wetting the leaves, which can encourage fungal diseases in our moderate-to-humid climate. Overhead watering can be okay if done early in the morning, allowing the leaves to dry before nightfall. If we're having a particularly wet summer, you might need to water less frequently.

Signs of underwatering include wilting leaves and blossom end rot, while yellowing leaves can indicate overwatering. Mulching around the base of the plants helps retain moisture and regulate soil temperature, which is especially helpful during those summer heat spells.

Sun Golds are vigorous indeterminate tomatoes, meaning they'll keep growing and producing all season long. They need strong support to keep them off the ground and prevent them from becoming a tangled mess. Tall, sturdy cages or strong stakes work best.

Install your support at planting time to avoid disturbing the roots later. As the plant grows, gently weave the stems through the cage or tie them to the stake with soft twine. Regular training will help keep the plant manageable and improve air circulation.

Sun Golds are notorious for their sprawling growth habit, so pruning is essential to keep them under control and maximize fruit production. Focus on removing suckers, which are the small shoots that grow in the "V" between the main stem and the branches. Pinch them off when they're small.

Leave the main stem and the fruiting branches. Prune regularly throughout the growing season, especially after a period of rapid growth. In late summer, around the time we start thinking about the first frost in early October, you can top the plants to encourage the remaining fruit to ripen.

You can expect your first Sun Gold harvest from early July through late August, depending on when you transplanted them. The tomatoes are ready to pick when they turn a vibrant orange-gold color and feel slightly soft to the touch. They're also intensely sweet at this stage.

Gently twist or snip the tomatoes from the vine, being careful not to damage the plant. The more you harvest, the more the plant will produce. As the first frost approaches in early October, harvest any remaining green tomatoes and bring them indoors to ripen. They'll still develop that signature sweetness, though maybe not quite as intensely as vine-ripened ones.

Here are a few common problems you might encounter with Sun Gold tomatoes in the Midwest:

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: Heavy watering or rain after a dry spell, causing the fruit to absorb water faster than the skin can expand.
• How to fix/prevent it: Water consistently to avoid the dry/wet cycle. Mulch to maintain even moisture. Harvest promptly when ripe.

Over-production:

• What it looks like: So many tomatoes that the plant struggles to support them, leading to broken branches or fruit not ripening properly.
• What causes it: Sun Golds are just naturally prolific, especially with our fertile soil and adequate rainfall.
• How to fix/prevent it: Prune regularly to improve air circulation and focus the plant's energy on fewer fruits. Harvest frequently to prevent the plant from becoming overloaded.

Early Blight:

• What it looks like: Brown spots with concentric rings (target or bullseye pattern) on lower leaves first, spreading upward. Leaves yellow and drop.
• What causes it: Fungal disease (Alternaria solani) that thrives in warm, humid conditions. Spreads via soil splash onto lower leaves.
• How to fix/prevent it: Remove and destroy affected leaves (don't compost). Mulch to prevent soil splash. Water at the base, not overhead. Improve air circulation through spacing and pruning. Copper fungicide slows spread. Rotate crops yearly.

Midwest Specific Challenges: Our moderate-to-hot summers and moderate-to-humid conditions, combined with wet-summer rainfall, can create an ideal environment for fungal diseases like early blight. Consistent watering is crucial, but heavy rains can also lead to cracking. Regular monitoring and proactive measures are key to a successful harvest.

Companion planting can give your Sun Golds a boost. Basil is a classic companion, improving the flavor of the tomatoes and repelling pests. Carrots and parsley attract beneficial insects that prey on tomato pests. French marigolds deter nematodes and other soil-borne pests.

Avoid planting brassicas (like cabbage and broccoli) near tomatoes, as they can stunt their growth. Fennel inhibits the growth of many plants, including tomatoes. Corn can also compete with tomatoes for nutrients and sunlight.