Sun Gold Tomato in Zone 10B — Desert Southwest

Sun Gold Tomato is a must-grow in our Desert Southwest gardens. The explosion of sweet, tangy flavor is incredible, and they're perfect for snacking straight off the vine or tossing into salads. Plus, that vibrant orange color just brightens up any dish! They're a prolific producer, too, giving you a steady supply throughout our long growing season.

Sure, we have to contend with extreme heat and alkaline soil here, but with careful timing and a few tricks, you can absolutely have a bumper crop of these delicious tomatoes. Our 349-day growing season gives us a head start on many other regions. Let's get growing!

Start your Sun Gold Tomato seeds indoors from mid December through early January, about six weeks before you plan to transplant them outside. This gives them a strong head start before our temperatures really start to climb. Use seed trays or small pots filled with a good seed-starting mix.

Keep the trays warm (around 70-75°F) and provide plenty of light – a grow light works great. Remember to water from the bottom to avoid damping off. Our very-early spring character means we need to be on top of things!

Transplant your Sun Gold Tomato seedlings outdoors from late January through late February. This avoids both the peak of winter cold and the worst of the summer heat. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Plant them 24-36 inches apart to give them plenty of room to grow. Even in late January, be mindful of any surprise cold snaps that can sometimes come through our area. If a freeze is predicted, cover your young plants.

Sun Gold Tomatoes are thirsty plants, especially in our arid Desert Southwest climate. They need consistent moisture to produce those juicy, flavorful fruits. During the cooler months (late January through March), aim for about 1-1.5 inches of water per week, watering deeply a couple of times a week.

Once the extreme heat kicks in (May onwards), you'll likely need to increase that to 2-3 inches per week, possibly even more during the monsoon season. Stick your finger about 2 inches into the soil – if it feels dry, it's time to water. Water at the base of the plant to avoid wetting the leaves and promoting fungal diseases, which can still pop up with monsoon moisture.

Signs of underwatering include wilting leaves and blossom end rot. Overwatering can lead to yellowing leaves and root rot. A good layer of mulch, like straw or wood chips, will help retain moisture in our dry air.

Sun Gold Tomatoes are vigorous, indeterminate growers, meaning they just keep on climbing! They need strong support to handle their prolific growth and heavy fruit load. A tall, sturdy tomato cage or a strong staking system works 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 stakes. This will keep the plant upright, improve air circulation, and make harvesting easier.

Pruning is essential for managing Sun Gold Tomato plants in our small Desert Southwest gardens. If left unpruned, they'll quickly take over! Focus on removing suckers – those small shoots that grow in the "armpit" between the main stem and a branch.

Pinch them off when they're small. Also, prune the lower leaves as the plant grows to improve air circulation and prevent soil-borne diseases. Start pruning a few weeks after transplanting and continue throughout the growing season. As we approach the first frost in late December, you can top the plant to encourage the remaining tomatoes to ripen.

You can expect your first harvest of Sun Gold Tomatoes from late March through mid May, depending on when you transplanted. The tomatoes are ready to pick when they turn a vibrant orange-gold color and are slightly soft to the touch. The flavor should be intensely sweet at this stage.

They'll often drop from the vine when they're perfectly ripe. Gently twist or snip the tomatoes from the plant, being careful not to damage the stems. To encourage continued production, harvest regularly. As the first frost approaches in late December, harvest any remaining green tomatoes and let them ripen indoors.

Here are three common problems with Sun Gold Tomatoes in the Desert Southwest:

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 after a dry spell. Our monsoon season can trigger this. The fruit absorbs 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: A huge amount of tomatoes, all ripening at once. Can overwhelm you!
• What causes it: Sun Golds are naturally prolific, and our long growing season encourages even more production.
• How to fix/prevent it: Succession planting (planting a few plants every few weeks) can help spread out the harvest. Give away extras to neighbors!

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, which can be an issue during our monsoon season.
• 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.

Desert Southwest Specific Challenges: Our extreme heat can stress tomato plants, making them more susceptible to problems. The arid air can also lead to blossom end rot if watering isn't consistent. Monitor your plants closely and adjust your care as needed to help them thrive in our unique climate.

Companion planting can give your Sun Gold Tomatoes a boost in the Desert Southwest. Basil repels tomato hornworms and other pests while also improving the flavor of your tomatoes. Carrots loosen the soil and deter nematodes. Parsley attracts beneficial insects like hoverflies that prey on aphids. French marigolds repel nematodes and other soil pests.

Avoid planting brassicas (like cabbage and broccoli) near tomatoes, as they can inhibit tomato growth. Fennel also inhibits growth, and corn can attract the same pests that bother tomatoes.