Campbell 33 Tomato

Start seeds indoors 6 to 8 weeks before your last spring frost date. Sow seeds 1/4 inch deep in seed-starting mix, keeping soil temperature around 70 to 80 degrees Fahrenheit for reliable germination. Provide 14 to 16 hours of light daily under grow lights to prevent leggy seedlings.

Harden off seedlings over 7 to 10 days by gradually exposing them to outdoor conditions. Transplant outdoors after the last frost date when soil temperature reaches at least 60 degrees Fahrenheit, spacing plants 24 inches apart with 36 inches between rows. Bury the transplant deeper than it was growing in the pot; tomatoes develop adventitious roots along buried stems, strengthening the plant.

Harvest tomatoes when they develop their characteristic deep red color, typically 60 to 69 days after transplanting. Fruits are ready when they yield slightly to gentle pressure but remain firm. Pick tomatoes in the morning when they're coolest, gently twisting and pulling them from the vine or using pruning shears to avoid damaging the plant. For processing and canning, harvest fully ripe fruit at peak color.

Campbell 33's determinate growth habit means it requires minimal pruning compared to indeterminate varieties. Remove lower leaves once the plant begins flowering to improve air circulation and reduce disease pressure, particularly for fungal infections like Late Blight and Powdery Mildew. Avoid aggressive pruning that removes more than one-third of foliage at a time, as the compact plant needs its leaves to support fruit development.