I'm new to the forum, and I have an "Endless Summer" hydrangea which was planted in 2011, on the north side of our property in partial sun. We are in hardiness zone 5b. We DO NOT trim this plant, and every year it leafs out great, but we have never gotten more than 1 or 2 blossoms all summer long. In our neighborhood, the house next door has hydrangea that bloom profusely.

In 2020, we planted 2 more "Endless Summer" on the south side in full sun, and they also do not bloom. I have attached a photo of the first plant. What am I missing?

Welcome to NGA, garyackernet. A few questions first please… Which variety of Endless Summer Collection are these plants? Where are they located (city-wise)? About how tall are they now (I could not gauge this from the picture)? What type of hydrangea does the neighbor grow: https://plantaddicts.com/types...

Hello?

luis_pr said: Hello?

Patience. Not everyone is on this forum every day....

Sorry... I did post a reply and an image, but for some reason, when I logged back in now it did not show up. It previewed, but perhaps I didn't go back to hit finish. So I will try again....
1. I looked up the variety of the plant in the image, it is "Twist-n-shout" planted in 2011. It has never produced more than a couple of blooms during the season.
2. The bush is about 4 feet tall.
3. We are located in a rural area in a valley but we are at elevation 1452 asl. (445 Whitney Valley Hgts. Almond, NY 14804)
4. The plant is facing north and gets mainly morning sun.
5. I was not able to find the variety of the neighbor's plants (didn't know)

Here is an updated photo..

What variety and height are the 2020 ES Collection plantings that are also not blooming?

There are 2 each 2020 Endless Summer® The Original Big Leaf Hydrangea
Hydrangea macrophylla Tailmee PP15,298. They are 24 inches in height. I found no buds on either plant all summer. These are in an area of mostly full sun.

Thanks

Ensure that you are not using fertilizers high in nitrogen like some Miracle-Gro formulations. Consider instead lower nitrogen and good phosphorus levels provided your soil has no nutrient deficiencies or toxicities. You can use Holly-tone and apply it at full strength by your average date of last frost in mid-to-late May and re-apply it again at half-strength at the end of June (about 3 months prior to your average date of first frost in the latter part of September).

Twist-n-Shout can get up to 5 feet tall. The new growth that begins to grow in spring 2023 will develop bud set as soon as the stems are tall enough to trigger bud set and to immediately open. Since Twist-n-Shout is now 4 feet tall, it seems to be close to blooming. But that is unfortunately very close to your average date of first frost. First frosts may kill the flower buds if temperatures drop sufficiently, the plant has no mulch, the plant is not frost protected with sheets/frost cloth/etc. and the soil is not deeply watered the night before.

Endless Summer The Original also reaches a height of about 5 feet and those specimens, at two feet of height only, may also have difficulty blooming earlier if the stems do not achieve a proper bud set height. Hydrangea Tailmee PP15,298 (probably a typo) is actually Endless Summer The Original, aka, Bailmer.

More direct sun can also help break dormancy earlier as the soil will get warmer faster, melt the snow faster and promote root spring growth (usually triggered around the low 40s).

If tweaking the fertilizers does not produce better results, consider replacing those tall cultivars by more compact varieties. You can currently find varieties that top out at an estimated height of 1 feet to 3 feet. From the Endless Summer Collection, consider Summer Crush or Pop Star (3 feet for both). From the Let's Dance Collection, consider Blue Jangles, Starlight, Sky View, Rave, Diva, Big Easy, Big Band, ¡Arriba! and Wee Bit Giddy (some of these can be from 1-3 feet tall). At high elevations above sea level, also consider the Tuff Series, although these cultivars exclusively produce lacecap form blooms, not mophead form blooms. You can view these collections at endlesssummerblooms.com (scroll down a little to view the variety names, go right/left to change the name and finally click on the variety name) or at provenwinners.com (search for "Let's Dance" or "Tuff"). Select a variety whose maximum advertised height is 3 feet or less.

Thank you very much for this guidance. I will definitely look to encourage these existing plants per your advice, and at the same time, I am going to do some new plantings in other spots in our garden, using your suggestions for varieties. I do think that my problem has been frost damage, I believe we did have a late spring frost that affected some of the other gardens in the area. I really appreciate your time and expertise.

Remember that these are remontant cultivars that produce two flushes of blooms, typically one flush in spring and another flush in late summer/fall. Late frosts would reduce or eliminate the spring blooms only but they would not explain why there are no blooms now in your remontant cultivars. The second flush of blooms typically occurs about now so it would not be impacted by late frosts.

To address damage from spring late frosts and common lake effect snow and to ensure reliable spring blooms from old wood, either (1) set up winter protection in the fall/early winter or (2) mulch, cover the plant with frost cloth/sheets/burlap and water deeply the night before. Also consider deadheading all spent/brown blooms every fall to reduce their weight on the stems and protect brittle stems from breaking/bending due to common cases of heavy, wet snow there. These spring protective measures need to persist until your average date of last frost (around the 2nd-3rd weeks of June).

Fertilizer, sun and cultivar changes would address a lack of blooms from ES cultivars in late summer/fall. All of the shrubs currently have until the 3rd-4th weeks of October (your average date of first frost) to produce blooms off the second flush of ES blooms. But it is possible that an unusually early frost may zap them, making any blooms short-lived. Note: keep abreast of changes to the forecast averages at higher elevations as this winter season is considered a strong El Niño year.