When hydrangeas are in full bloom they are covered with large flowers that will fill any gardener with joy and pride. Their ease of growing makes them a popular choice among those with green thumbs and those new to gardening. However, despite that ease, it is possible for home gardeners to make common mistakes when growing these plants. Lorraine Balato, author of Success With Hydrangeas, shares with Express.co.uk what are some of these mistakes when it comes to big-leaf hydrangeas – the most common variety to grow.
1. Wrong amount of sunlight
According to expert, hydrangeas need ample sunlight to thrive. She said: “Large-leaf hydrangeas need about a half day of sun, ideally in the morning.
“Don’t worry if you can only provide afternoon sun, you can still get flowers. You just need to keep an eye on the moisture level in the soil to provide enough rehydration for them when needed.”
For those living in the South, Lorraine says to be careful about afternoon sun, but for those northern gardens, a more important part of their siting is protecting them as much as possible from winter conditions.
She explained: “To do this, consider planting them under the protection of winter-persistent barriers such as evergreens (conifers, rhododendrons, azaleas) or plants that hold their brown leaves, such as beech, parrotia, sumac and oak.” .
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“Other barriers could be a fence, a neighbor’s house, a shed, or even an Adirondack garden chair or other lawn furniture to block the prevailing cold winds and icy precipitation.”
2. Too Much Fertilizer
Next gardeners need to make sure their plants are strong and healthy enough to produce flowers (which take a lot of energy from the plant). Lorraine said: “You do this by fertilizing your hydrangeas, ideally in early spring around August 1st.
“Rose compost or granular shrub fertilizers have the right mix of nutrients to do the job. Fertilizing in fall distracts them from impending dormancy, so leave them alone at that time of year.
However, if hydrangeas are planted near a lawn, they can take up fertilizer from it – too much and the plant will not flower.
The expert advised: “Check to see that your hydrangea is not getting nitrogen from an adjacent fertilized lawn, especially if the plant is on the underside of that lawn or if a rotary spreader is used.
“If so, then all that ‘accidental’ nitrogen your hydrangea gets is encouraging it to make leaves, not flowers. See if you can either move the plant or fertilize that somehow. Can prevent hydrangea from reaching the roots.
3. Too Much Water
If excess nitrogen isn’t the problem, Hydrangea Pro urges owners to “take a look at their watering habits.”
She explained: “When you see your plant wilting in the sun it is a normal reaction to water it. Most of the time, this won’t be necessary because hydrangeas rehydrate as soon as the sun stops. They seep back into the surrounding soil and rise back up within a few hours.
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“Consider watering any spot until the sun is away from the plant for a while to see if it comes back. You may have to wait till the next morning. If it’s still flagging, then by all means go ahead and give it a drink. Then inspect the mulch to see if it is sufficient to help retain that precious moisture in the soil.
“Keep in mind that too much water at the roots is just as bad as too little. That excess water can rob your plant of needed oxygen and cause it to rot, eventually killing it. But more importantly, too much Over-watering will cause your plant to produce leaves, not flowers.
4. Pruning at the wrong time
The last and “most common cultural reason your plant may not flower” is pruning at the wrong time. Big leaf hydrangeas begin to develop their flower buds for the next year as early as August.
Those buds take several weeks to form and then remain on the stems until the next season.
Lorraine warns: “Any time you cut that plant between August and when you see buds—not just leaves—you run the risk of cutting ‘dormant’ flowers.
“Despite the fact that there are stems that look dead, most are alive. You can easily test the viability of a stem by scratching it, if it shows green, it is alive.
5. Your hydrangea isn’t hardy for your location
It is possible that gardeners have a plant that is not hardy to their location. To find out, check the tag or ask a knowledgeable gardener. This is especially true if the plant came in one of those attractive foil-wrapped packages, according to the expert.
She said: “They are known as ‘pot plants’ and are grown strictly for the abundant flowers, preferably indoors. They usually appear in stores all over for events such as Easter and Mother’s Day It is very rare that a potted plant will bloom again when kept outside.”