If you plant them before nighttime temps stay above 55°f (13°c), you risk stunted growth and transplant shock. · to help you maximize your tomato crop, here are 20 common mistakes that can ruin your harvest and practical solutions to avoid them. · whether youre a first-time grower or a seasoned gardener, watch out for these 10 common tomato-growing mistakes that can sabotage your success. · in this article, we cover 15 common tomato growing mistakes and how to avoid them. · in this article, i’m going to share with you how we helped our tomato plants out of their misery and walk you through a few common (and some uncommon) mistakes that might be killing your tomato yield. Tomatoes hate cold soil. Planting tomatoes in poorly drained or nutrient-deficient soil can severely impact their growth. Poor soil preparation. · the key is to know how to start off your plants right and avoid practices that can result in disease-riddled plants. Heres a look at the 9 most common tomato growing mistakes , along with tips for avoiding each blunder at planting time and all the way through to harvest. From planting too early or too deep, to overwatering and neglecting pruning , these tips will ensure that your tomato plants thrive and produce an abundant, flavorful crop.