I remember several years ago a stand-up comedy routine being performed where the comedian referred to a Thermos vacuum bottle and said something to the effect of, “I love these things. You put hot liquids or stew in this, and it’ll keep it hot for a long time. Or, you can put a cold liquid and it’ll keep it cold for a long time, too.” Then, after a dramatic pause and an exaggerated puzzled look, he delivered the line, “how does it know?!!!” It was a good quip, and for those that don’t know the insulating power of a vacuum — a space devoid of atmosphere — it indeed was a mystery. Nonetheless, it was good for a laugh.
I remember my first encounter with hydrangeas and finding out that the same variety can be influenced to produce either bluish or reddish tinted blooms. Same plant, but depending on how your treat it, you can get it to produce different colors. How does it know?
Hydrangeas will do quite well if provided their basic needs. They enjoy a reasonably good soil mix, and moist to drier soil. They don’t like soggy soil, as they can root rot. Having said that, they do need ready access to moisture. Once hydrangeas are established, they are fairly drought-resistant. To be able to bloom, they need a good amount of sun. A location that allows for direct sunlight for a good part of the day, followed by shade or bright shade is appreciated by the plant.
Planting under a tree can be problematic for a couple of reasons. First, these blooming dynamos need lots of sun to pull off the prolific display of blooms each season. The second reason is just as significant: tree roots are stronger competitors than hydrangea, so as time goes on, the hydrangea will find itself with less and less resources at its disposal. This is true even if you dig out tree roots when you plant your shrub. Over a relatively short period of time, the tree roots will grow back.
So, if you do have a hydrangea under a tree presently, keep an eye on it. If it tends to lose vigor the longer it’s been in your yardscape, consider transplanting it — but only when it’s dormant. You’ll know it is asleep when it has lost all its leaves — typically late fall or early winter.
It’s also important to keep in mind the mature size of most hydrangea varieties when you choose a planting site. Allowing for the plant to reach four feet tall by four feet wide should work just fine. However, check the plant tag, as there are sizable varieties that can get significantly larger than that!
There are many species of hydrangea grown worldwide, but only six are common in the United States. Hydrangea is native to southern and eastern Asia as well as North and South America. Flowers are usually produced from early spring to late autumn. The primary blooms are actually comprised of small individual flowers that collectively create a sizable splash of color.
How do you pronounce “hydrangea?” I mutilated the word for years — so let’s see if you can save you some horticultural embarrassment! Try this phonetic spelling on for size: “hye-DRAN-jee-uh.” To coach you a bit further, the first syllable is like greeting someone, “hi.” The second sounds like “drain.” The last two are pretty clear. The first and second syllables are said a tad slower than the last two. Practice it a bit and say it with confidence! The word itself has an interesting meaning. “Hydrangea” is a combination of the Greek words “hydor” (water) and “angos” (vessel). Some think this pertains to the plant’s need to have access to water and its cup-shaped flower. That’s a bit of a stretch for me.
What about the ability to change color displays? Actually, not all hydrangea varieties have the ability to change color. Some of the white varieties will stay white, no matter what you do. It’s genetic. There are also varieties that will only display reddish hues and can’t change to blue. So, if being able to have differing color displays is important to you, read the label, or do a bit of research before heading to the nursery.
Since we live in a hotter climate, it’s also difficult to get truly red blooms. Under the right conditions, you can get pink and deep pink coloration. Hydrangea plants that are being grown in containers are a better candidate for color changes, simply because soil pH is much easier to modify than in open ground. If you have a variety that can change colors, you really can influence the display. Many online gardening advisers recommend adding lime or baking soda diluted in water to raise the pH (alkalinity) of the soil. Higher alkalinity soils will stimulate pink or reddish coloration. But, hold on! We live in Utah, the “poster child” for alkalinity! I’ll bet you will find your soil is already alkaline. Even container plant growing mixes will tend to change to a higher pH due to the alkaline content in our water.
To get blue tints, you will need to lower the pH, using acidifying fertilizers, or sulfur-based fertilizers, such as aluminum sulfate. Once the soil is more acidic, the plant can then access both aluminum and iron compounds which will stimulate bluish blooms.
This chameleon-like characteristic doesn’t occur immediately, though. Modifications to soil pH and nutrients will affect next season’s blooms, not the current one. This is because hydrangeas produce main flower clusters on the tips of shoots that were produced the last season. Think of it as a lesson in delayed gratification! And, remember that your soil will continually tend to move towards higher pH (alkaline) levels. We live next to the Great SALT Lake, remember?
Your hydrangeas will benefit from deadheading as well. Depending on the variety, you may get more blooms, but that is not always the case. There are varieties that can generate new blooms after old ones have been taken off, or if there was cold weather damage. These types are said to be “remontant;” being able to bloom more than once a season. Even for those types that can’t generate more blooms, keeping the plant cleaned up by removing spent bloom clusters improves the appearance of the plant. Discard the flowers in your compost pile, not under the plant, as this can lead to a breeding spot for disease.
Care does need to be taken when deadheading, as well as pruning. When removing spent blooms, snip them off just below where the cluster began. The blooms for the next season will come from shoots generated this season, so care must be taken not to destroy shoots or their terminal buds. If these portions of the plant are lost to excessive winter cold or indiscriminate pruning, the plant will probably fail to bloom the next season.
To help protect more tender plantings from excessive cold and to help assure a stronger display of blooms, wire cages can be erected around plants and then filled with leaves or chopped straw to help mitigate the effects of the cold. This may sound like excessive effort, but that depends on how much you value the blooms. Time will tell from season to season what you’ll need to do to get the results that are desirable to you for the sweat expended!
Want to learn something cool this coming weekend and hang out with others that really enjoy life in their yard? Have we got something for you! A few years ago, Maggie and I decided to build a warm-weather outdoor sink to make it easier to wash veggies, splash some water on our faces on a hot day, or to quickly fill up a watering can. It was a great decision. We decided to film how to build one and post it on our YouTube channel. It’s been a hit with viewers from all around the world building their own water stations! We’ll be doing live demonstrations this coming Saturday, May 28, at the Tooele Home Depot. Stop by and see us at one of four sessions at 10 a.m., 11 a.m., 1 p.m. or 2 p.m. We’ll see you there!
Jay Cooper can be contacted at email@example.com, or you can visit youtube.com/dirtfarmerjay for videos on gardening, shop skills, culinary arts and landscaping.