Anyway, my starter tomato plants that are in plastic cups and 4 inch clay pots are approximately 6 inches high and sitting in my garden window. When should I plant them outside?
I'm in S.E. Michigan and the weather has finally started to warm up..........70 degrees today and warming over the weekend...but the temps over night will probably drop down to about 50 degrees.........
Wait until your nighttime temps are solidly 50 degrees and above before planting out your tomatoes. Warm nighttime temps are a must!
In the meanwhile, toughen them up by putting them outside during the day in a protected area to get some wind on them, or run your hands over them to move them around a little a few times a day.
When you plant them, you can remove the lower leaves and plant them DEEP. The stems are hairy and roots will grow from the stem parts that are underground, making for a hardy, healthy tomato plant. Make sure you use tomato cages or some way of staking them so they don’t fall over in the dirt. (You get nicer tomatoes that way.)
Also, when you plant, put a handful of Bone Meal in the planting hole, and when your tomato starts to set fruit, give it another top dressing of bone meal and water it in. This prevents Blossom End Rot, which isn’t a disease, but a calcium deficiency. (We’ve all been there!)
During the rest of the season fertilize with a well-balanced fertilizer such as Miracle Grow, or your choice of organics, following the package instructions. Mulch your plants with straw, but don’t mulch up close to the stem - leave a little open ring there so you can water directly at the roots. Tomatoes have furry leaves and don’t like getting wet. Yes, you can’t avoid if it it rains, but they’ll tolerate that. Avoid overhead sprinkling if you can.
As the tomato plant grows, pinch out the ‘suckers’ that will appear in the ‘crotch’ of the plant where stems meet the main trunk of the plant. They do nothing but zap energy from the plant as a whole.
Just ask if you’re having problems along the way. Best of luck! :)