|Common Name||Revolution Hydrangea|
|Size||12-24” tall by 12-24” wide|
|USDA hardiness Zones||5-9|
|Sun / Shade||full sun to part shade|
|Soil||Average garden soil|
|Moisture||moist but well drained|
|Disease and Pests||none known|
|Landscape use||foundations, containers, cutting gardens, urban gardens, mixed borders|
|Market appeal / Uniqueness||Repeat flowering hydrangeas often disappoint because they bloom so sporadically. Buy this plant and enlighten your garden with a blooming revolution.|
|Bloom Time||May-Sept on new and old wood|
Angela and Linda’s Garden Notes:
We know you will love the long lasting, strong flowers of the Everlasting series with their variety of colors, handsome foliage, and long-lasting flowers. As the flowers age, they change from one exciting color to the next. You will enjoy many colors at one time as each flower lasts for months. Each stem is a bouquet, and even a young plant will give you months of blooming enjoyment.
One of the most commonly asked questions at garden centers worldwide is – How do I prune my hydrangeas?
It’s easy, really!
First, some definitions:
There are three ways in which hydrangeas flower– those that flower on new wood, those that flower on old wood, and now there are some newer selections that flower on new and old wood and therefore they require little or no pruning each year.
Old Wood means branches that have been on the hydrangea since the summer before the current season.
New wood means branches that will develop on the plant during the current growing season.
Method I is for hydrangea types that bloom on old wood (last year’s branches). Prune these hydrangeas only in the summer before August, before they set their bloom buds for the next year. This group of hydrangeas produce flower buds on hydrangea stems around August, September or October for the following summer’s blooms. If those stems are removed (pruned) in the fall, winter, or spring, the bloom buds will be removed, and there may be little or no bloom the following summer (usually June/July for the northern hemisphere).
Method II is for hydrangeas that flower on new wood (new branches). This type of hydrangea is determined to flower every single year, no matter how they are treated. Prune these plants in the late summer after they have bloomed. They cannot be pruned is in the spring when they are preparing to flower, because you will cut off the flower buds.
Method III is for hydrangeas that flower on both new and old wood. Prune these hydrangeas only if they are getting too large for the space or if you want to remove old flowers. The best time to prune them is after they flower in the late summer. If you prune them much beyond late summer, you will risk removing the flower buds that are developing on the current branches.
The next most commonly asked question is – How do I change the color of the flowers?
To change the flower from Blue to Pink:
For hydrangea flowers to be pink, the plants must not take up aluminum from the soil. If the soil naturally contains aluminum, you must try to keep it away from the hydrangea’s system. Try this if you would rather have pink flowers:
- Add dolomitic lime several times a year. This will help to raise the pH. Shoot for a pH of about 6.0 to 6.2 (If it goes above 6.4 hydrangeas may experience an iron deficiency, which will make their leaves turn yellow). Since hydrangeas take up aluminum best at lower pH levels, raising the pH will help to keep the bluing effect of aluminum out of the hydrangea’s system.
- Use a fertilizer with high levels of phosphorus. Phosphorus helps to prevent aluminum from creeping into the system of the hydrangea. Choose a fertilizer close to the ratio of 25/10/10 (Phosphorus is the middle number)
- In areas that naturally produce blue hydrangeas (soils with aluminum), consider growing pink hydrangeas in large pots. If hydrangeas are grown in pots, it would be best to use potting soil, not garden or top soil, since these mixes should not have aluminum in them. In a pot, it will be much easier to control the requirements for growing pink hydrangeas.
To change the flower from Pink to Blue:
To make hydrangea flowers blue, aluminum must be present in the soil. To ensure that aluminum is present, aluminum sulfate may be added to the soil around the hydrangeas.
We recommend that a solution of 1/2 oz (1 Tbsp) aluminum sulfate per gallon of water be applied to plants throughout the growing season. Important: Make sure your soil is a little wet before you do this because the mixture can burn dried out roots.
To make the aluminum available to the plant, the pH of the soil should be low (5.2-5.5). Adding aluminum sulfate will lower the pH of the soil. Another method for lowering the pH is to add organic matter to the soil such as coffee grounds, fruit and vegetable peels, grass clippings etc.
If the soil naturally contains aluminum and is acidic (low pH) the color of the hydrangea will automatically be blue and/or purple.
The choice of fertilizer will also affect the color change. A fertilizer low in phosphorus and high in potassium is helpful in producing a good blue color (25/5/30 is good). Potassium is the last number). Super-phosphates and bone meal should be avoided when trying to produce blue.
Note 1: Unfortunately, it is virtually impossible to turn a hydrangea blue forever if it is planted in soil with no aluminum and that is highly alkaline (chalky). You have to be very diligent in keeping the soil properly conditioned on a continual basis as stated above.
Perhaps the best idea for growing blue hydrangeas in an area with alkaline soil is to grow them in very large pots using lots of compost to bring the pH down. Our recommendations for bluing also work for a potted plant. Reduce the strength of the Aluminum sulfate to 1/4 oz per gallon of water. In a pot, it is much easier to control the requirements for bluing and since these are hardy to USDA zone 5, most of you should be able to grow the Everlasting™ Series in a pot outside and leave it outside all winter.
Note 2: Planting hydrangeas near a concrete foundation or sidewalk will often affect the color since the pH of the soil may be raised considerably by lime leaching out of these structures, making it difficult to obtain blue.
Growing Hydrangea macrophylla Container Plants
- Cuttings are grown in 50 cells to be shifted to 8”, and in 18 cells to be shifted to 2-3 gallons in late spring to early summer
- Accept liner deliveries in April/May depending on area of the country
- Plant by late spring to early summer to guarantee a strong root system and to avoid crowding, which often leads to mold and mildew.
- To avoid Pythium, never prune a cutting just before, or just after planting
- Pinch 2 x before July 7th
- 4-5 weeks after the last pinching spray with Banner at the recommended rate (active ingredient Propiconzale) Banner is a fungicide, and is highly effective as a PGR on Hydrangeas. Repeat as needed
- By September, plants should have 12-20 branches
- Buds begin to develop in late summer to early autumn, as soon as average day temps range from 55-60 degrees.
- Buds remain dormant through the winter, and require temps just above freezing (34-36 degrees) to complete vernalization.
- 6-8 weeks or 1000 hours of chilling is required.
- This can be achieved in a temperature controlled greenhouse.
- If growing outside in colder climates, vernalization will occur naturally, but protection from fluctuating temperatures in the fall or early spring that could damage the buds is imperative
- Although Hydrangeas require med-high light levels, too much direct sun will damage flowers and buds. Continue to provide enough supplemental light throughout the winter months to keep buds healthy and to keep plants from becoming leggy
- Monitor water use. Excessive water is one of the easiest ways to adversely affect a crop, often leading to blind stems, bud abortion, and ultimately, Pythium.
- Drip irrigation is preferred. Keep irrigation zones small to allow custom watering zones, and make sure your pots and the table or ground they sit on have adequate drainage
Pest and disease control:
- Hydrangeas can be sensitive to Aphids, Spider Mites, Botyritis, Mildew and Pythium.
- Before using any fungicides or pesticides please trial on a small scale, since Hydrangeas have proven to be sensitive to some treatments.
- An application of Imidacloprid (Merit) in the beginning of the season will help eliminate insect problems, but grower must remain vigilant throughout the growing season to combat insects and disease. (systemic)
- To avoid fungal problems, keep plants free of all dead foliage on pots, tables, and ground.
- A preventive fungicide is strongly suggested just before plants begin to actively grow in spring
- During flowering, the flowers are more sensitive to burning. Provide water on a regular basis
Coloring of the flowers:
- Changing the color of the flowers from pink to blue depends on the pH of the soil and the concentration of aluminum ions present in the media.
- The recommended pH for growing Hydrangeas is 5.5
- For blue flowers, the pH should never exceed 5.5. Reducing the pH below 4.8 may result in damaged plants with growth impairment.
- At a pH over 6.5, iron is no longer available, flowers cannot turn blue, and the foliage often becomes chlorotic, resulting in yellow leaves.
- White varieties cannot be colored blue.
- In short, both aluminum potassium sulfate (alum) and aluminum sulfate, are essential tools in manipulating the flower color of mop-head Hydrangeas.
- In September and November apply 15 grams potassium-aluminum (kali- alum) to a 3 gallon container (or adjust to the rate provided for the size container you are growing in)
- Or use aluminum-sulfate at a 17-18% rate (given in liquid form) at the end of September or the beginning of October. At the rate of 6 grams on a 3 gallon container (or adjust to the rate provided for the size container you are growing in)
- In March and May reduce rate of aluminum-sulfate 17-18% to 5 grams per 3 gallon, or apply potassium-aluminum again
- A missing, or untimely application of alum often results in muddy blue colors
- Be sure to follow the schedule and increase the amount of alum where irrigation water is alkaline (high in calcium)
- In some cases, it might be beneficial to use rain water, or soft water to limit the calcium accumulation in containers