Whenever someone asks, “How fast do hydrangeas grow?” the answer lies in two things, primarily: the cultivar and the care. Of all the different varieties of hydrangeas, each one has it own specific growth rate if grown under ideal conditions for that particular cultivar. On the whole, most hydrangeas grow fairly rapidly. Of course, this is always affected by the care given to the plant and can vary, sometimes widely.
As a general rule, hydrangeas need moist, well-draining soil. How fast do hydrangeas grow in well-draining soil also depends on how often it is fertilized and with what. Professionals sometimes advocate the use of special fertilizer mixes to produce the fastest growth rate and the largest, showiest blooms. Others prefer a more relaxed, organic method of providing food for their hydrangeas consisting simply of manure and compost.
A middle-of-the-road approach is to use a slow-released, balanced commercial fertilizer once or twice a year. People growing hydrangeas in the South fertilize with best results by applying it first sometime in May, with another dose of fertilizer in late July.
Northern hydrangea gardeners need only apply fertilizer once in June. One-quarter cup of commercial fertilizer works well for small hydrangeas, while larger bushes do best using one to two cups broadcasted around the drip line. Do not apply fertilizer next to the trunk of hydrangea bushes.
How fast do hydrangeas grow with the use of only manure? Gardeners have reported excellent results with this back-to-nature approach. One person relates applying manure to an older hydrangea bush that had only bloomed weakly and sporadically for several years.
After only one application of manure, this plant, whom the gardener had thought was simply played out, is now the showiest shrub in the landscape. The only complaint from this particular gardener was the proliferation of weeds after the manure application, of which she overcame by placing several layers of newspaper over the weedy area, then covering with mulch.
Do not Add More Stress
Before applying any kind of fertilizer, organic or commercial, it is important to make sure your bushes are healthy. How fast hydrangeas grow means little if the plants are having problems with their root systems or have some kind of disease or insect infestation. Fertilizer will only add to the stress the plants are already encountering. So before fertilizing, make sure hydrangeas do not appear sick or wilted and clear up any other problems they may be having beforehand.
Sometimes things beyond our control affect hydrangeas growth rate. Heavy winds can cause blooms and buds to become damaged or for entire branches to break off. A sudden, unexpected cold snap can cause both foliage and buds to freeze and delay or retard growth.
Insects can invade literally overnight and decimate foliage. However unlikely, there are simply some things beyond our abilities to foresee, and as such, the only thing we can do in instances like these are to repair the damage as best as possible, then continue onward toward getting the plants back into primo condition.
In all truth, how fast do hydrangeas grow should be secondary to how healthy are your hydrangeas. Once you address any health issues your bushes may be having, you are well on your way to being able to anticipate the rewards of big beautiful blooms. The size of hydrangeas is not what counts; it is their ability to thrive that is important.