Why isn't my hydrangea blooming?
One of the most popular plants I sell are hydrangeas. From small to large blossoms of white, red, pink, blue, purple, bi-color and the list just seems to get expanded more and more each year.
When you break down the name, hydrangea, the Latin "hydra" translates into water. These plants do like moist areas but have been known to grow in dry well draining soils as well.
First, let's break down the types of hydrangeas....
#1 Hydrangea macrophylla- These are rounded "snowball " like flowers that prefer part sun to a shaded situation. Some are remontant, or repeat bloomers while others seem to be quite finicky and bloom when they feel like it.
I am often asked why my hydrangea is not blooming. Improper timing of trimming on these varieties are the main culprit. The rounded macrophylla varieties of hydrangeas should only be pruned in mid to the end of August when flowers are at the end of their bloom cycle. They will start setting flower buds late August and into September for the next year. Improper timing of pruning could cause flower buds to be trimmed off. Late frosts or snows like we had in previous years caused a lot of flower buds to be frozen and negated flowering for the year.
Insufficient light is another possibility. Hydrangeas do like shade, but deep shade will not yield many, if any flowers.
If you do have a hydrangea which seems stubborn and you have not pruned at the wrong time, I always suggest taking a sharp spade and digging on one side only the plant as if you were going to transplant it to a new location. This usually shocks the plant into blooming the next year. The stress to the plant causes it to go into survival mode and procreate with flowers. It's not 100% a cure but works a lot of the time. Also, a good shot of fertilizer like espoma's holly-tone will help with producing flowers as no plant will do well if it is starving.
Check the flow chart out by proven winners to see why your hydrangea may not be blooming.
The pH of your soil also has a lot to do with the color of your hydrangeas. If you add lime and raise the ph of soil, your flowers will be pink, the higher the ph, the pinker the flowers. Conversely, if you add aluminum sulphate or soil Sulphur and lower the ph, your flowers will be blue. The aluminum sulphate really gets flower colors almost an electric blue. I have some clients which experiment with varied combinations of lime and aluminum sulphate, one puts lime on the left side and aluminum sulphate on the right, this yields mixed colors on the same plant.