Getting Your Hydrangea Flowers to Bloom

Big, beautiful foliage but no or few hydrangea flowers on those showy plants? Here are some tips on how to get your hydrangeas to bloom in spectacular fashion.

Why Hydrangeas Don’t Bloom

Horticultural experts in growing hydrangeas say there are three basic reasons why hydrangea flowers fail to bloom. They’re either pruned too drastically in fall, planted in the wrong location, or are affected by a late spring freeze. If the latter, and new growth appears only at the bottom, it’s likely the plant won’t bloom this year. Never prune after August, as this is when hydrangeas set their buds for the next blooming season.

Check The Location

Hydrangeas are fairly easy to grow if they’re planted according to the right zone – and in the right location in the garden. Hydrangea flowers like a location that does not get hot afternoon sun, but morning sun and afternoon shade is perfect.  As for soil, hydrangeas do best in slightly acidic soil, with a pH balance of 4.5 to 6.5.

Make sure the hydrangeas aren’t planted beneath hardwood trees. No matter how much the tree roots are dug up, they’ll inevitably interfere with the hydrangea bushes and not permit the plants to thrive. Hydrangeas also do not get sufficient sun beneath dense tree cover.

If it’s necessary to transplant the hydrangea from one location to a better one in the garden, do so in the fall or when all the leaves have fallen off. Dig up as much of the hydrangea root ball as possible (it will be very heavy) and move it to the new location. Water deeply as soon as planted.

Amending The Soil

Add organic materials such as manure or compost, or chemical fertilizers. Many hydrangea aficionados swear by commercial manure for a more organic approach to amending the soil. Slow-release, balanced fertilizer should be applied 1 to 2 times a year. Osmocote needs to be released under the soil, while 10-10-10 can be applied twice during the summer.

Performing a Soil Test

Unsure of the soil’s pH? Since hydrangea flowers like a slightly acidic soil, depending on the color you want (blue hydrangea flowers like acid soil, while reds and pihnks prefer more alkaline or neutral soil), get a soil kit from a university extension center and perform a soil test. Once the results are in, steps can be taken to either increase the acidity or alkaline content.

Remember that soil acidity is also affected by soil composition, rain and irrigation.

How To Encourage Blue Hydrangea Flowers

If hydrangeas are pink and the desired color is blue, this means raising the acidity to the point where the plant will produce blue blooms. Soak the soil around the plants several times at weekly intervals with aluminum sulfate. Apply at a rate of ¼ ounce per gallon of water. Powder form can also be worked into the soil, but concentrations vary according to each brand, so read and follow instructions carefully.

How To Encourage Pink or Red Blooms

Lime lowers the acidity of highly acidic soil – and pink or red hydrangea flowers like a more alkaline soil. Apply lime at a rate of 1 pound to each 10 square feet around the hydrangea plants 1 to 2 times a year. Be patient to allow the plants time to adjust and change bloom color.