The most common heritage tomato problems are cracking, blossom end rot, and fungal diseases. Your heirloom plants face more trouble than modern hybrids do. They lack built-in disease resistance so you need to watch them closely. Knowing what to look for helps you catch problems early.
I've dealt with every one of these issues in my own garden over the years. My first season with Cherokee Purple taught me hard lessons about watering and disease. Now I watch my plants closely and jump on problems before they spread through the whole patch.
Cracking happens when your tomatoes swell too fast after a heavy rain. The skin can't stretch quick enough so it splits open. You'll see rings around the stem or lines running down the sides. For tomato cracking prevention, keep your watering steady and don't let the soil dry out between rains.
Blossom end rot heirloom growers see shows up as dark sunken spots on the bottom of your fruits. This comes from calcium problems in the plant, not the soil. Uneven watering keeps the plant from moving calcium where it needs to go. Water deep and steady to stop this from hitting your harvest.
Heirloom tomato diseases include early blight, late blight, and septoria leaf spot. You'll spot early blight by the brown rings on your lower leaves first. Late blight moves fast and can kill plants in days. Remove sick leaves right away and throw them in the trash, not your compost.
Thin heirloom skins and odd shapes make your fruits easy targets for bugs and rot. Hornworms can strip a plant bare in just a few days if you don't catch them. Check the underside of leaves where they like to hide. Pick them off by hand or spray with BT to protect your plants.
Catfacing creates ugly scars and lumps on your fruits from cold weather during bloom time. The damage happens when temps drop below 55°F (13°C) while flowers are setting. Cover your plants on cold nights or wait to plant until the weather warms up for good.
Good spacing helps prevent many of these problems before they start. Give your plants at least three feet of room so air moves freely through the foliage. Apply thick mulch around the base to keep soil from splashing onto your lower leaves when rain falls.
Pick varieties that do well in your local conditions to avoid fighting the same battles year after year. Some heirlooms handle heat better than others. Some fight off blight longer. Ask other gardeners in your area what works for them and build on their success.
Read the full article: Best Heirloom Tomato Varieties to Grow
