Sun Gold Tomato in Zone 6B — Mountain West

Sun Gold tomatoes are practically sunshine in fruit form, and their intensely sweet flavor makes them a must-grow for any Mountain West gardener. These little gems are perfect for snacking straight from the vine, adding a burst of flavor to salads, or even grilling for a smoky-sweet treat. Plus, the satisfaction of harvesting baskets of these beauties after our long winters is unmatched.

Our high altitude, intense sun, and cool nights can be challenging, but with a little planning, you can absolutely succeed with Sun Golds. Our 163-day growing season is just enough time to get a fantastic harvest if you start smart. Timing is key.

Starting Sun Gold tomatoes indoors is the way to go here in the Mountain West. We need to give them a head start to beat our short growing season. Aim to sow your seeds late March through mid April, about six weeks before you plan to transplant them outside.

Use seed trays or small pots filled with a good seed-starting mix. Keep them warm – around 70-75°F – and provide plenty of light. A sunny windowsill often isn't enough, so consider using grow lights. Be sure to water from the bottom to encourage strong root growth and prevent damping off. Remember, spring here can be unpredictable, so starting indoors gives your tomatoes the best chance.

Transplant your Sun Gold tomato seedlings outdoors early May through early June, once the danger of frost has passed. Before planting them in the ground, harden them off by gradually exposing them to outdoor conditions for about a week. Start with an hour or two of shade, increasing the time and sun exposure each day.

Plant your seedlings 24-36 inches apart in well-drained soil. Keep an eye on the weather forecast because we can still get some surprise cold snaps in early May. Be ready to cover your young plants if a frost threatens.

Sun Gold tomatoes are thirsty plants, especially in our dry Mountain West climate. Consistent moisture is crucial for these prolific producers. The biggest challenge is fruit cracking, which happens when they get too much water after a dry spell, so consistent watering is essential.

During the peak of summer, give your Sun Golds a deep watering two to three times a week, providing about 1-2 inches of water each time. Stick your finger about two inches into the soil – if it feels dry, it's time to water. Water at the base of the plant to avoid wetting the foliage, which can increase the risk of disease in other climates, though our low humidity usually mitigates this.

Signs of underwatering include wilting leaves and slow growth. Overwatering can lead to yellowing leaves and root rot. A layer of mulch around the base of the plant helps retain moisture and keeps the soil temperature even.

Sun Gold tomatoes are vigorous indeterminate growers, meaning they'll keep growing taller and producing fruit all season long. They need strong support to stay upright and healthy. Without it, they'll sprawl all over the ground and be more susceptible to pests and diseases.

Tall, sturdy cages or strong stakes work best for Sun Golds. Install your support system at planting time to avoid disturbing the roots later. As the plant grows, gently tie the main stem to the stake or weave it through the cage to keep it contained.

Pruning is essential for managing Sun Gold tomatoes. If you don't prune, they'll become a tangled mess. Focus on removing suckers, which are the small shoots that grow in the "armpit" between the main stem and a branch. These suckers will steal energy from fruit production.

Prune suckers regularly throughout the growing season, especially early in the morning when the plant is less stressed. Also, remove any yellowing or dead leaves from the bottom of the plant to improve air circulation. Toward the end of the season, as we approach our first frost around early October, you can pinch off the top of the main stem to encourage the plant to ripen any remaining fruit.

The best part about growing Sun Gold tomatoes is the harvest! You can expect your first ripe tomatoes early July through late August, depending on when you transplanted. Sun Golds are ready to pick when they turn a vibrant orange-gold color and are slightly soft to the touch. They should practically fall off the vine when you gently tug them.

Harvest regularly to encourage the plant to keep producing. Even as the first frost approaches in early October, don't give up. Pick any remaining green tomatoes and bring them indoors to ripen on a windowsill or in a paper bag. The flavor won't be quite as intense, but you'll still get to enjoy the fruits of your labor.

Even with the best care, you might encounter a few problems with your Sun Gold tomatoes. Here are three common issues in the Mountain West:

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. Heavy watering or rain after a dry spell causes the fruit to absorb water too quickly.
• How to fix/prevent it: Water consistently. Mulch to maintain even moisture. Harvest promptly when ripe.

Over-production:

• What it looks like: So many tomatoes that you can't possibly eat them all.
• What causes it: Sun Golds are just naturally prolific.
• How to fix/prevent it: Share with neighbors, make sauce, roast them, or dry them.

Early Blight:

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

Mountain West Specific Challenges: Our intense sun can sometimes scorch the fruit if the plants aren't properly shaded or watered. The dry air can also stress the plants, making them more susceptible to problems. Consistent watering and some afternoon shade during the hottest part of the summer are key.

Companion planting can help your Sun Gold tomatoes thrive.

Good companions:

• Basil: Repels pests and improves tomato flavor.
• Carrots: Loosen the soil and don't compete for nutrients.
• Parsley: Attracts beneficial insects.
• French Marigolds: Repel nematodes and other soil pests.

Bad companions:

• Brassicas (cabbage, broccoli, cauliflower): Can inhibit tomato growth.
• Fennel: Inhibits growth of many plants, including tomatoes.
• Corn: Attracts tomato pests like tomato hornworms.