PRUNING YOUR OLD WOOD FLOWERING HYDRANGEAS
Now that you have completed cutting back your new wood blooming hydrangeas, it's time to look at what's happening with your old wood plants. Which ones are these?
Your old wood plants include hydrangea macrophylla (big leaf), hydrangea serrata (mountain), hydrangea quercifolia (oak leaf) and hydrangea petiolaris (climbing). Even if your plant is a rebloomer it retains old wood flower power and buds can be there that formed on last year's growth.
You have a green light to take care of purely old wood bloomers like oak leaf hydrangeas, climbing hydrangeas, non-reblooming big leaf hydrangeas, and non-reblooming mountain hydrangeas now. Work on the obvious stuff like deadheading to neaten up the plant. Cut the spent flower down to the first set of live buds.
Inspect your plants for the 3Ds (dead, damaged, diseased wood) and carefully remove them, ideally at ground level with a lopper depending on the issue. Don‘ t ignore inward growing branches, pencil-thin stems, and any stems that are rubbing.
If you find some old canes that look like this one with peeling bark, or this pebbly one
cut them at ground level. They won't produce a flower ever again.
And if your plant has a lot of old stubs at the base from prior year's cuts like the one in this photo
eliminate those stubs to unclog the trunk. You'll improve air flow and deprive slugs of hiding places while they lay in wait to nip on your plant.
If you're not sure if your stem is alive, scratch it with your fingernail. If it shows green, it’s a live stem.
Wayward stems might be present at the base of your plant. Now is the moment to get rid of them. But be cautious since they may have been low enough to develop roots, granting you a new plant. Snip them off from the mother plant and pot them up for a few weeks before setting them out in the garden for their next life. A little TLC and encouraging fertilizer while they are in pots will get them off to an excellent start. Cool, huh?
It's unlikely that your oak leaf and climbing hydrangeas will need any pruning before they flower. Look them over for the 3Ds, inward growing, rubbing, and pencil-thin stems. You might have a low-lying branch or two on your oakleaf that you can designate for later removal. You can delay action until it gives you its magnificent flower this season.
And if your climbing hydrangeas need a haircut badly as mine does, wait until it flowers before you do that. Mine has buds on it so I know I'm in for a treat in a couple of months.
For your big leaf or mountain hydrangeas that are rebloomers, you can also get rid of the stems that have rebloomed. They won't provide any more flowers for you. They look like this, with flower stems coming off the sides:
Use your loppers to take them off as close to the ground as possible. Here's where you must be extremely careful not to dislodge the new buds/leaves that you see at the base of your plant. Some of them might be the start of new stems that will generate flowers at the tips before the season ends. If you can't get to that stem now, mark it with a twistie or pipe cleaner for removal in the fall when the coast is clear. Or cut it a few inches from the ground; it can come out altogether at a later date.
You can also remove the pebbly stems and those with peeling bark. Cut as close to the ground as you can get without endangering any new spring growth.
Do not deadhead your rebloomers until you are well past your frost free date. When you cut the tips of your rebloomers, you release the hormones in the stem to generate the sleeping flowers along its length. Once those sleeping buds break dormancy, they are susceptible to being killed by late season frosts and in one cold snap, you can kiss your second round of flowers goodbye.
Once the flower buds appear on your plant, you can cut anything that demands it. Deadheading is a perfect idea as that tip cutting will release the growth hormones in the stem.
There is pruning aftercare to do now. First up is fertilizing with a granular rose fertilizer or shrub fertilizer. No 10-10-10. No plant uses nutrients in equal amounts. Applying products like 10-10-10 just contributes to run-off and pollution issues. Follow the directions on the label. Second, check your irrigation if you have it, and, third, finish with mulch. It can be compost, leaves, bark, etc. And of course, disinfect/sharpen your tools. You don't want to transfer any pathogens to the next plant you work on, and your pruners need to be razor sharp for that next plant.
Since I wrote about pruning new wood bloomers last time, I have found a terrific video for pruning panicle hydrangeas (hydrangea paniculata). It uses ‘Limelight’ as the model. The principles apply to all panicle hydrangeas. https://youtu.be/vd3AuBso30U.
A reminder: Mother's Day is less than 2 weeks away. If you want to gift someone with a signed copy of my hydrangea book, you still have time to do that. In fact, you have two options. One is to order from my site by going HERE. I will inscribe your book upon request.
Or you can come to Sam Bridge Nursery in Greenwich, CT this Saturday (May 4) where I'll be giving 2 presentations and selling/signing my book. Here's the info:
Sam Bridge Nursery & Greenhouses, 437 North Street Greenwich, CT 06830
Topic: Blooming Hydrangeas, 11 a.m., Free, http://sambridge.com/events/
Topic: Shrubs, The New Perennial, 1.30 p.m. Free, http://sambridge.com/events/
OK. Time to get outside and prune those plants. Tick-Tock!
Your old wood plants include hydrangea macrophylla (big leaf), hydrangea serrata (mountain), hydrangea quercifolia (oak leaf) and hydrangea petiolaris (climbing). Even if your plant is a rebloomer it retains old wood flower power and buds can be there that formed on last year's growth.
You have a green light to take care of purely old wood bloomers like oak leaf hydrangeas, climbing hydrangeas, non-reblooming big leaf hydrangeas, and non-reblooming mountain hydrangeas now. Work on the obvious stuff like deadheading to neaten up the plant. Cut the spent flower down to the first set of live buds.
Inspect your plants for the 3Ds (dead, damaged, diseased wood) and carefully remove them, ideally at ground level with a lopper depending on the issue. Don
If you find some old canes that look like this one with peeling bark, or this pebbly one
 |
| Old hydrangea canes that can be removed |
And if your plant has a lot of old stubs at the base from prior year's cuts like the one in this photo
 |
| Big leaf hydrangea (macrophylla) with clogged trunk. |
eliminate those stubs to unclog the trunk. You'll improve air flow and deprive slugs of hiding places while they lay in wait to nip on your plant.
If you're not sure if your stem is alive, scratch it with your fingernail. If it shows green, it’s a live stem.
 |
| Live stem on hydrangea shows green when scratched. |
Wayward stems might be present at the base of your plant. Now is the moment to get rid of them. But be cautious since they may have been low enough to develop roots, granting you a new plant. Snip them off from the mother plant and pot them up for a few weeks before setting them out in the garden for their next life. A little TLC and encouraging fertilizer while they are in pots will get them off to an excellent start. Cool, huh?
It's unlikely that your oak leaf and climbing hydrangeas will need any pruning before they flower. Look them over for the 3Ds, inward growing, rubbing, and pencil-thin stems. You might have a low-lying branch or two on your oakleaf that you can designate for later removal. You can delay action until it gives you its magnificent flower this season.
And if your climbing hydrangeas need a haircut badly as mine does, wait until it flowers before you do that. Mine has buds on it so I know I'm in for a treat in a couple of months.
For your big leaf or mountain hydrangeas that are rebloomers, you can also get rid of the stems that have rebloomed. They won't provide any more flowers for you. They look like this, with flower stems coming off the sides:
 |
| Spent stem from a reblooming hydrangea. |
Use your loppers to take them off as close to the ground as possible. Here's where you must be extremely careful not to dislodge the new buds/leaves that you see at the base of your plant. Some of them might be the start of new stems that will generate flowers at the tips before the season ends. If you can't get to that stem now, mark it with a twistie or pipe cleaner for removal in the fall when the coast is clear. Or cut it a few inches from the ground; it can come out altogether at a later date.
You can also remove the pebbly stems and those with peeling bark. Cut as close to the ground as you can get without endangering any new spring growth.
Do not deadhead your rebloomers until you are well past your frost free date. When you cut the tips of your rebloomers, you release the hormones in the stem to generate the sleeping flowers along its length. Once those sleeping buds break dormancy, they are susceptible to being killed by late season frosts and in one cold snap, you can kiss your second round of flowers goodbye.
Once the flower buds appear on your plant, you can cut anything that demands it. Deadheading is a perfect idea as that tip cutting will release the growth hormones in the stem.
There is pruning aftercare to do now. First up is fertilizing with a granular rose fertilizer or shrub fertilizer. No 10-10-10. No plant uses nutrients in equal amounts. Applying products like 10-10-10 just contributes to run-off and pollution issues. Follow the directions on the label. Second, check your irrigation if you have it, and, third, finish with mulch. It can be compost, leaves, bark, etc. And of course, disinfect/sharpen your tools. You don't want to transfer any pathogens to the next plant you work on, and your pruners need to be razor sharp for that next plant.
Since I wrote about pruning new wood bloomers last time, I have found a terrific video for pruning panicle hydrangeas (hydrangea paniculata). It uses ‘Limelight’ as the model. The principles apply to all panicle hydrangeas. https://youtu.be/vd3AuBso30U.
A reminder: Mother's Day is less than 2 weeks away. If you want to gift someone with a signed copy of my hydrangea book, you still have time to do that. In fact, you have two options. One is to order from my site by going HERE. I will inscribe your book upon request.
Or you can come to Sam Bridge Nursery in Greenwich, CT this Saturday (May 4) where I'll be giving 2 presentations and selling/signing my book. Here's the info:
Sam Bridge Nursery & Greenhouses, 437 North Street Greenwich, CT 06830
Topic: Blooming Hydrangeas, 11 a.m., Free, http://sambridge.com/events/
Topic: Shrubs, The New Perennial, 1.30 p.m. Free, http://sambridge.com/events/
OK. Time to get outside and prune those plants. Tick-Tock!
