FAQ
If you live in a colder area or frost zone, you might want to protect your hydrangea in winter. The best way is to plant it in an area away from drying winter winds. When well into the winter, spray with fungicide and secure the branches together with twine. Pack mulch around the plant's base, wrap with a thermal blanket, and then cover with thick plastic. Remove everything the following spring after the last frost.
The following zone information is based on the USDA Plant Hardiness Zone Map; not Sunset's Western Climate Zone system.
The most cold hardy of the hydrangeas are Arborescens and Paniculatas; both are rated for zones 4-9. Petiolaris and the subspecies varieties are also rated for zones 4-9. Quercifolia is rated for zones 5-9, but requires heat (not sun) in the summer and cold winters to bloom well. Japonica Coerulea is also rated for zones /5-9.
Macrophyllas (mopheads) are generally fine in zones 6-9 with some protection in the winter. The Normalis variety (lacecaps) are known for being somewhat hardier than the mopheads. The cold hardiest of the mopheads seem to be David Ramsey, Oak Hill, All Summer Beauty, Nikko Blue, General Vicomtesse deVibraye, and Sadie Ray. Serratas and Aspera are rated for zones 6-9.
If you live in hot and humid climates (above zone 8), some extra care will be needed for your hydrangea. Most hydrangeas in your area must be kept out of the direct afternoon sun. You will also find that more water will be needed to keep the soil moist. Keep the plant sheltered from drying winds as leaves tend to lose moisture quickly. Bloom time and color may differ in your area due to the temperature.
We extend this information to you as a guide to help you in your decision making about which hydrangeas should do well in your area. With proper care you can successfully grow hydrangeas in a zone rated somewhat higher or lower with good success and they will wake from their leafless state to bring you the flowers of spring, summer, and fall.
My hydrangeas aren't the color I had hoped for. How do I change the color?
The color of the hydrangeas will vary considerably due to the type of soil they are growing in. The blues are best in acid soil. The amount of aluminum available in the soil and the ability of a particular variety to absorb it will control the degree of blueness. The reds and pinks enjoy an alkaline or neutral soil. The whites will stay white but usually enjoy the same conditions as the reds and pinks.
You'll need to raise the acidity of the soil to encourage "blueing" of the flowers. This can be done by adding aluminum sulfate. Some products are liquid and soaking the soil around the plant several times at weekly intervals in the spring and again in the fall with aluminum sulfate. Powder form can be worked in the soil but concentrations vary depending on the brand. Read the instructions on the box carefully before application.
Apply lime to lower the acidity of high acid soil to encourage pink to red blooms. The lime should be applied at a rate of one pound to every ten square feet of surface area once or twice a year until the desired color is obtained.
Please note color correction takes some weeks or even months to occur, so you'll want to be patient. Rain, irrigation, and soil composition also affect the acidity of your soil.
I hardly had any blooms this spring. Am I not pruning correctly, or are the hydrangeas getting too much sun?
A blooming problem is likely pruning, although too much sun can contribute to the problem. Most hydrangeas bloom on old wood, and if you prune too harshly there are no buds for the next blooming season. We recommend trimming just 10-20% of the plant, or just above a "node." If you prune too much or too late, you cut off the wood that will produce the blooming buds. We trim our personal garden in the fall as we've found the more harshly and later we prune, the less blooms we have the following summer.
Sun can also hurt the blooming ability of a hydrangea. Too much direct sunlight drains the plant of moisture. If the foliage is still green and healthy, the hydrangea is most likely using all the water to retain its health and the bloom is left with nothing. The best environment for most hydrangeas is morning sun and afternoon shade.
Unseasonably low temperatures after a mild winter also cause a lack of blooming on hydrangeas. Most hydrangeas bloom on old wood and if the leafed-out plant is hit by late spring frost, the buds freeze and the hydrangea won't bloom.
Several white hydrangeas (Paniculatas and Annabelle) bloom on new wood and are thus more hardy. You may prune these varieties any time (spring or fall) and they will still produce flowers.
When is the best time to plant hydrangeas and when should I order?
The best time to plant hydrangeas depends on your local climate, but as a general rule of thumb you can plant in the spring after the last chance of frost. Planting in the fall or summer is also an option if you live in a more mild climate.
You can order hydrangeas at any time. We typically ship on the first Monday or Tuesday after your order date or another day/date if you make a specific request. We do not ship in December or January and only ship in February weather permitting. To our customers in colder environments, we suggest spring ship dates after the threat of frost is gone.
How do you ship your hydrangeas?
We use UPS and USPS Priority and ship two-day or three-day service depending on weather conditions. We do not ship bare root like many mail order companies, and have found that it is much less shocking to the plant if we ship the hydrangea with some soil. We wrap the root ball with soil in a small plastic bag, and wrap this and the foliage in some newspaper. We then package your hydrangea very carefully in even more newspaper to cushion the plant from any bumps along the way.
How should I plant my new hydrangea?
Choose a location that does not get hot afternoon sun. Prepare a hole approximately twice the size of the root ball. Hydrangeas like slightly acid soil (with pH 4.5 to 6.5). If your soil is heavy, incorporate some humus-rich material (bark dust or compost) with the dirt you took out. Backfill the hole as you plant such that your finished job leaves the surface (top of the root ball) about 1 1/2 inches above the original soil level. If done right, the settled new soil will not leave a depression for water to stand in. Thoroughly water the plant and keep the soil moist in hot weather until the hydrangea is established. Use an annual application of balanced fertilizer, bearing in mind that some fertilizers may affect your soil pH levels.
Some of the smaller varieties of hydrangeas will thrive in a pot. For instance, consider 'Pia', 'Tovelit', 'Trophy', 'Amethyst', or 'Miss Belgium'. Growing in pots makes it easier to change the color, too!
Can you tell me the difference between 1, 2 and 3 year old plants and can I expect blooms this summer?
Our hydrangeas come in three sizes. The 1 year old size has been grown in a 4" or 3.5" container for one growing season and is approximately one year old. Foliage is typically 3" tall. These are starter hydrangeas and should be protected for a few seasons. Our 2 year old size is grown in a one gallon container for one growing season. The root ball is generally 6" square and the foliage 8-18" in height (but sometimes as tall as 24").
The 3 year old size is also a container grown plant that has been in a two or three gallon container for at least one growing season. The size of the root ball will differ by variety but is generally 10" square. Foliage height of the delivered plant(s) vary due to our vigorous pruning schedule; we prune often to spur new branches and increase the spread of the plant. As a result the foliage height of 3 year old size plants is generally 12-24" (and sometimes as tall as 36").
Hydrangeas grow quickly. The heights indicated by variety are the ideal mature size with pruning.
We cannot guarantee the plant will bloom, but do guarantee a well rooted and well branched plant. Most hydrangeas bloom on old wood, meaning that blooms come from last year's growth. As such, blooms on our hydrangeas may take at least one year to develop because we prune often to ensure a well branched plant. But our plants will eventually produce many blooms because our plants are so well branched. That said, you won't necessarily be "bloomless" the first year either.
Why are there spotty leaves on my hydrangea?
Black or red spots on the leaves? Improve the air circulation around the plant by removing the damaged leaves and other vegetation. Also water the base of the plant and not from above. Add some peat moss or bark or mulch to keep the moisture near the ground. Avoid over watering, too. Water and some chemicals cause the spots on the leaves.
Why do my hydrangeas look tired?
Do the stems and leaves perk up after watering? If they do perk back up, it's normal on hot humid days for hydrangeas to look droopy. If they don't perk up after watering and the leaves' edges are slightly burnt and brown, it could be too much water sitting around the roots. Cut droopy leaves off or cut the stem just above a healthy leaf node. Hydrangeas like well-draining soil and if the water stays around the roots, the hydrangea will die from the inside. Improve the drainage around the roots. This involves replanting the hydrangea with well-draining soil (humus, peat moss, bark, compost, or pumice - crushed volcanic rock sold under the trade name Perlite).
What about powdery mildew?
The powdery mildew is from the environment of the plant. Too much moisture is around the leaves. Place some mulch, peat moss, or bark at the base of the hydrangea to protect the leaves from the moisture in the ground. On hot humid days, this is a common problem easily fixed with layering the material over the ground. You may also use a horticultural oil to wipe the leaves clean of the powdery mildew.
Why can't I find a particular variety?
Can't find what you're looking for? We are growing over 350 varieties of hydrangeas so if you're looking for a special variety, just let us know. Maybe we have it growing in a little corner of the nursery.
Can we visit Hydrangeas Plus?
We are not open to the public at this time. Besides, there really isn't much to see. We cut the hydrangeas often so that blooms are a rarity. Our potting mix is also very alkaline and because there is no soil used in our mix, we see unusual colors in our hydrangeas. If you'd like to see our hydrangeas in a nursery near you, please tell your local garden center about us. Or, a slide show presentation or question and answer session can be arranged through our office. Just call us to discuss the options.
How can I learn more about hydrangeas?
Join the American Hydrangea Society for newsletters, hydrangea and other presentation information. The mailing address is:
The American Hydrangea Society
PO Box 11645
Atlanta, GA 30355
The annual membership fee is $15.
Does Sudden Oak Death affect hydrangeas?
According to up-to-date studies, Sudden Oak Death (SOD) doesn’t affect hydrangeas and the hydrangea genus is not a host species. The US department of Agriculture has deemed 28 plant families as natural hosts for Phytophthora ramorum, the fungus like organism that has been found to cause Sudden Oak Death. Commonly found hosts are Rhododendron, Pieris and Camellias. For more information, visit our Oregon Department of Agriculture site at http://oda.state.or.us.