para_chan
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Building a raised bed with existing hydrangeas

I have two hydrangeas growing where I'd like to create a raised bed (at most 6"). Would it be better to dig them up and replant them at a higher level, or would they be alright with that much dirt on the crowns?

Also, last winter, both hydrangeas were killed to ground level. I'm in zone 8a and we had one bad frost. Neighbors still have big bushy hydrangeas, so I know it wasn't *that* bad of a freeze. Both plants grew new leaves and branches from the roots this spring, but if they get killed back again this winter, how do they ever get to be bushes?!

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rainbowgardener
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hydrangea hardiness

I'm thinking that it was not the frost that set your hydrangea back. Most varieties of hydrangeas are quite cold hardy. I'm here in Ohio (zone 6) and my oak leaf hydrangea does quite well. The annabelle and pee gee hydrangeas are also quite cold hardy. Some of the mophead and lace cap ones are not as hardy, but I have seen some around here. You didn't say what kind you have.

I don't really know the answer to your raised bed question, but erring on the side of caution would be to replant them at higher level, especially if you are talking about the 6". They do say for the less hardy hydrangeas to provide a heavy mulch to help it get through the winter. That would be equivalent to 2-3", so if you are just raising the level a little it should be ok.

luis_pr
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Sorry to hear about your plant, para_chan. What hydrangea type and variety do you have?

When replanting, I would place them as they are now in the new hole such that they are either level or slightly higher than the surrounding soil. Do not plat the crown under the surrounding soil. Settling may cause them to sink a little so compensate by placing them just a little higher (not much... say, 1/2 inch? 1/4 of an inch?) than the surrounding soil.

Under normal circumstances, your hydrangea should have returned back from its deep slumber without winter damage. To make sure that all is well, try these suggestions:

* hydrangeas are dormant during winter but they will need a constant supply of water at reduced levels because the roots are still growing so make sure to supply water during dry winters while the ground does not freeze. Otherwise the stems could die for lack of water and since they are dormant, you would not notice until they start to leaf out from the crown.

* mulch is the winter protector for hydrangea roots so make sure that you always have about 3-4" of mulch early in the Fall and replenish any lost during winter if the plant is located in a windy location. Extend the mulch up to the drip line or a little beyond.

* go easy on the fertilizer. Do not fertilize after July so the plant will go dormant in time for the arrival of winter and do not use fertilizers high in nitrogen. Otherwise, the plant will stay in growth mode as winter arrives and the stems could be killed by sudden early (or even late) cold winter snaps.

* In the northern states, fertilize with about 1/2 to 1 cup of manure, compost or cottonseed meal in June or July. In the southern states, fertilize twice in May and July. Mind you, that is for the whole year; hydrangeas do not need as much fertilizer as roses.

* Weak fertilizers such as coffee grounds, liquid seaweed or liquid fish can be applied throughout most of the growing season but stop in July too.

* Water the night before temps are forecasted to go well below freezing. Snow in the ground helps protect the roots too so feel free to leave it there.

* Make sure that lawn fertilizer pellets -normally containing a lot of nitrogen- do not land where the hydrangea roots are located.

Good luck this winter,
Luis

para_chan
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Thank you!

They're both mopheads, but I have no idea what type. One was dug up from a friend's garden and the other was bought at a redneck nursery.

I'm fairly sure that the ground didn't dry out for either bush. The ground doesn't freeze here, and we get a lot of rain. All the rain from the front of our roof is funneled to the area where the bushes are. I'll make sure to check on them this winter though.

luis_pr
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You could add some extensions if the area gets too much water. I had to do that in my existing house.

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Diane
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luis_pr wrote:
Under normal circumstances, your hydrangea should have returned back from its deep slumber without winter damage. To make sure that all is well, try these suggestions:

* hydrangeas are dormant during winter but they will need a constant supply of water at reduced levels because the roots are still growing so make sure to supply water during dry winters while the ground does not freeze. Otherwise the stems could die for lack of water and since they are dormant, you would not notice until they start to leaf out from the crown.

Good luck this winter,
Luis
Luis, I have two mophead and one lacecap Hydrangas. They are 10-15 years old. The mopheads flower pretty good but the lacecap had one flower this year and only a few last year.
The plant is quite large and looks healthy. I believe they flower on old wood.
If our freezing winters aren't killing the old canes I wonder if it is lack of water?
So you say to water if the ground isn't frozen?
It is frozen for most of the winter. So what should I do?
I think the huge slippery elm tree in the next yard, only about 15 feet away, takes all of the water. It does all spring, summer and fall.
Gardens are a little bit of heaven on earth.

https://s600.photobucket.com/albums/tt87 ... G00047.jpg

luis_pr
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Hello, Diane. When a hydrangea does not bloom, I like to ask if plant produced flower buds or not. No buds indicates that something happened between the time that flower buds are developed (July-Sept) until the time that the flower buds open in Spring (April-June). Macrophyllas that bloom on old wood should develop flower buds starting in July here thru August-September in the northern states; they should bloom somewhere around April thru May, approximately. Normal bud production, followed by a lack of blooms, means that something happened in Spring.

If you see the development of the flower buds into broccoli-shaped green immature blooms during early Spring (April-June) but you get no blooms, consider these causes: soil moisture problems in Spring; late frosts; pruning as the flower buds are opening; pests such as deer, squirrels, rabbits, etc.

If you do not see any broccoli-shaped early blooms in Spring, consider: the hydrangea is not hardy in your zone if it happens often (lace caps are normally ok up to Zone 6 but check; it depends on the variety that you have); watering issues (anywhere from July-September thru Spring), winter damage (temperatures are too low; winds dry out the stems), too much fertilizer (too much nitrogen in the Fall causes problems by keeping the plant in growth mode just as freezing temperatures hit; abundant levels also cause lack of flower production in Spring); mineral deficiencies (too little nitrogen or phosphorus).

The elm tree could also be causing problems as you suggested because elm trees do not have a dominant tap root system but rather have a larger number of roots with root hairs closer to the surface. If the hydrangea roots grow in this area, there will be competition for water and minerals. But from your description of the hydrangea looking well, I doubt that this is a problem now.

Heirloom macrophylla hydrangeas have to be rejuvenated now and then as they will get so large that they produce smaller blooms and/or fewer blooms. The timing for this varies greatly, but macrophyllas require some rejuvenation pruning every 5-10 years. If all the other causes are ruled out, this may be what ails your plant. To rejuvenate a hydrangea, prune the oldest 1/3 stems all the way to the ground on year 1. On year 2, prune the next 1/3 oldest and prune the remaining ones on Year 3.

Finally, if you have not done a soil test within the last 3-5 years, you may want to have one done to test for mineral deficiencies.

Do you have any pictures of the plants that you can share? Maybe this will give additional ideas.

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Diane
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Thank you so much Luis for such a detailed answer.
I don't have a picture of the lacecap, but I will take one, I hope, tomorrow. I use my DD's camera phone. :)
It isn't too much fertilizer...up until this year I have never fertilized them. :oops:
I don't prune them. I had read that nature takes care of that with old wood types. So I can't blame the elm although I do have to water them often on hot days.
It might be the spring frosts that we get. I have lost plants because of that. Or that the plants are just too old.
This is a pic of my youngest plant. About ten years old.

[img]https://i600.photobucket.com/albums/tt87/Dianesgarden/IMG00055.jpg[/img]
Gardens are a little bit of heaven on earth.

https://s600.photobucket.com/albums/tt87 ... G00047.jpg

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