Annuals/sickly ivy geraniums
I live in the Upper Peninsula of Michigan and the ivy geraniums I planted in flower boxes look pitiful. The flowers die very quickly and now the leaves are dying even faster. This summer has been very cool so far but I usually find geraniums very hardy. Could temperature be the culprit? Could I have gotten a bad batch from the nursery?
It's unlikely that you have "a bad batch." The things that will cause flowers and leaves to die include the following: too much water, too little water, and fertilizer burn. If the plant hasn't been fertilized regularly it can cause flower production to slow down, and cool weather can do this as well.
1. Over-watered plants usually turn yellowish all over before wilting or turning brown. Annuals might be getting over-watered if the drainage hole in the container is clogged. Also, annuals use less water in cool weather so if you're watering them on a "hot weather schedule" that could cause problems.
2. Under-watered plants will lose their lower, older leaves first - these will turn yellow and fall, while the top, newer leaves will stay green. The flowers will turn brown and dry up.
3. If a plant gets too much fertilizer in one dose, or is fertilized when the soil is dry, that pushes too much fertilizer salts into the plant tissues and causes fertilizer burn. Usually flowers and the edges of foliage turn brown first, but sometimes entire leaves brown as well. Never fertilize a thirsty plant (water well and let the plant absorb the moisture before applying fertilizer) and always use the recommended rate on the package.
I hope this helps!