Wintering Question

[msalcido]

I know fall isn't even here yet and I'm already thinking about winter. Just have a really quick question.

I have more potted hydrangeas than what will fit in my garage. I have a "pop" up green house. I was wondering if the hydrangeas will be OK during the cold winter months in the green house? My concern is this will not allow them to go dormant. I usually keep my potted plants (that are supposed to be indoor plants) out in the yard during the summer time and move them to the greenhouse during the winter. They all stay green.

By putting them in the greenhouse will this have an adverse effect on the hydrangeas?

Thanks in advance.

[luis_pr]

I would keep the potted hydrangeas outside until the fall weather makes them go dormant. Remember to water them if there is a chance of freezing temps. Our mild winter being what it is, 35 degress F may not happen until December but hopefully, the weather changes should make the plants go dormant sooner. You can then move them to the pop up greenhouse.

I have not had one of those pop up units but I saw a few for sale at Calloways. If they can maintain above freezing night temperatures inside, you may be fine putting potted plants in there. It would work great for things like my bougainvilleas! They are getting too troublesome to store inside nowadays. Just remember to water the hydrangeas once a week or once every two weeks; and of course, keep them mulched.

[msalcido]

Thanks Luis,
Yeah the "pop up" greenhouse works fantastic. We got this one at Calloways. I think you will be very happy with it, you should give it a try.

How do you know when they are dormant? Is it when all the leaves have fallen off? Also, do you protect the in ground hydrangeas? I had one last year, and didn't protect it and it did fine, however it only put out 3 blooms this season. Now that I have over 7 of them in ground, I want to make sure I do it correctly.

Thanks again for all your advice. It's greatly appreciated.

[luis_pr]

You can assume that the plants (in the ground or in pots) have gone dormant if the leaves dry out. No need to wait for the leaves to fall.

In this zone, the odds are good that you will not need to winter protect hydrangeas. But every now and then, it may be necessary. I remember a time recently, about 3-5 years ago, when the temperatures were pretty mild... in the 70s thru mid-or-late December. The hydrangeas and many other plants were fooled and I knew this was going to be bad (same thing happened to me in Atlanta decades ago. After I went on vacation, the temperatures plummeted, went below freezing and stayed under/slightly above freezing for almost a whole week. Result? Only two blooms that year. But no hydrangea shrubs or their stems died. If I had winter protected, I am sure I would have seen more blooms. Oh well. It does not happen often here though; since the odds are in one's favor, most people do not winter protect.

The only winter protection that is needed here is 3-4" of mulch. But there are two other things that you should make a habit of monitoring as they can result in fewer or no blooms:

1. Flower buds are the first thing to be aborted when the plant lacks moisture. When we have dry fall/winters, you need to water the plant because although they are dormant, they still need moisture. So during dry winters when one typically turns off the sprinkler, water once a week or once every two weeks during dry years (our ground does not freeze but if it were to freeze then do not water).

2. Stop fertilizing at the start of July. If you fertilize after this date, the plant may stay in "growth" mode and early frosts may kill flower buds. They may also kill tender new growth but it is unlikely it would kill a plant since the root system should be well protected by the soil, mulch and any snow on top of the mulch.

[msalcido]

The only winter protection that is needed here is 3-4" of mulch. But there are two other things that you should make a habit of monitoring as they can result in fewer or no blooms:

1. Flower buds are the first thing to be aborted when the plant lacks moisture. When we have dry fall/winters, you need to water the plant because although they are dormant, they still need moisture. So during dry winters when one typically turns off the sprinkler, water once a week or once every two weeks during dry years (our ground does not freeze but if it were to freeze then do not water).

So glad to hear they will only need mulching. I was prepared to do the whole chicken wire around each one and putting leaves over them. So only mulching will work! Great News!
As for the watering, I was aware to water only once or twice a week. Also when do we start fertilizing? Is it when the leaves start showing or is there a certain date?

Thanks again for all of your advice!

[luis_pr]

Sorry for the delay. My PC got infected and I have been unable to use it since mid-week last week. Looks like I am going to have to reformat the hard drive. Dimwits!

Fertilzing is an area where you do not have to worry about much if your soil is not defficient in minerals. I have forgotten to fertilize in some years with no impact to plant health or bloomage. Hydrangeas are not heavy feeders like roses so two applications of fertilizers will usually do here in the South (once in June in the North); for example, fertilize in April-May and June. Just stop fertilizing before July. A cup or half a cup of cottonseed meal should be good enough; or use manure or compost.

I add some amendments in April to acidify the soil and I add some weak fertilizers like coffee grounds as soon as they leaf out. Not much mind you. It depends on whether Starbucks has any when I stop by and if any are left by the time I get to the hydrangeas. I also re-apply acidifying amendments in the second half of summer some years, especially if I notice that the plants ask for it. Some years they do. Other years they do not. I try remember to do that again somewhere between June-August.

Believe it or not, I find winter a difficult time of the year to water since "the camellia incident". I tend to turn off the sprinkler in the winter when there is word of cold/freezing temperatures so the drip irrigation does not kick in. Well, I forgot to turn it back "on" and some time passed when we had no precipitation. One day I noticed a camellia bush whose leaves were starting to brown out. When I checked the soil, it was dry like a bone. When I checked the sprinkler, it was still "off". Oops!

Hydrangeas, because they are dormant and are not evergreen, cannot tell you if they need water during those dry winter times so I now check the camellias and azaleas for signs of leaving the drip irrigation turned off again. Ha! Oh meeeee....

[msalcido]

OH No. Sorry to hear about your PC. Hopefully everything will be OK.

I add some amendments in April to acidify the soil and I add some weak fertilizers like coffee grounds as soon as they leaf out. Not much mind you

Please forgive all my questions. What type of amendments do you use? Also, for the coffee grounds, what benefits do they have? I've heard of using them in a compost but not alone. I've been doing some research online about the different fertilizers to use and OMG are there so many different options/opinions.

Thanks again.

[luis_pr]

Our soil is not defficient in naturally occuring aluminum so to reduce the soil pH is use whatever amendments I happen to have available. It may be aluminum sulfate, garden Sulphur, liquid chelated compounds, green sand, etc.

If you are trying to correct iron chlorosis, liquid chelated compounds will do the trick faster.

The coffee grounds are a weak fertilizer; they contain some nitrogen (2%) and minor or a trace of phosphate, pottash and other minerals. It does not help keep the soil acidic because most of the acidity is lost when we prepare the coffee. It helps replenish some of these minerals (sometimes called trace elements). If you want to, you could also add them to your compost bin (if you have one).

[cynthia_h]

A secondary benefit of coffee grounds is that earthworms LOVE them. The worms will be attracted to the soil beneath the plants where you've placed the coffee grounds and will thus aerate the soil as they make burrows and generally "do their thing" in the region.

I sometimes just use a hand fork and scratch in compost or (if I'm really lazy/desperate) coffee grounds beneath my roses and water it in. Then, in the winter, which is when it rains around here, I see lots of earthworms "taking the air" beneath the roses during or after a hard rain, so I know that they've been living there.

I'm happy to let the earthworms aerate my soil; saves me the trouble!

Cynthia H.
Sunset Zone 17, USDA Zone 9

[msalcido]

Thanks Luis and Cynthia. Greatly appreciate it!

[msalcido]

Hi again,

So none of my potted hydrangeas have gone dormant. Temps are supposed to drop to 32 degrees tomorrow. Should I just water the plants and leave them outside or do I move them in? The planted (in ground) hydrangeas have started going dormant but not the potted ones?

As always, thanks for any and all advice.

[luis_pr]

I would bring them inside. The roots of potted plants are not as well protected from the cold temperatures as roots of plants in the ground. I am sure that at just 32 degrees, nothing bad will happen but play it safe and develop the habit of bringing them inside when the temperatures are going to be below freezing.

[msalcido]

Thanks Luis! I figured as much. I was concerned about moving them in and out. I guess they will be OK?

Hope you had a good Thanksgiving and have a great holiday season!

[msalcido]

Is there a way to force the hydrangeas in the pots to go dormant? With the exception of one, all the potted ones are still green and have lots of leaves on them. I'm concerned this will effect them for next Spring and I won't have any blooms?

Temps are in the low 30's this week and I have brought them all inside. They are in a room that gets sun and of course have the house temps which is kept between 68-72 degrees. Should I move them to garage where it is colder?

Thanks!

[luis_pr]

The only way to force them to go dormant is to reduce the amount of sunlight that they get and to expose them to cold -at or above freezing- temperatures. For example, tonight we will be dipping down to 33. Tempreatures a few degrees around freezing should help force the plants to go dormant. Monday we will dip into the upper 20s; that is a tad cold so bring them inside tomorow morning/afternoon.

Understand that these temperatures are actually quite mild to hydrangea flower buds. Depending on the hardiness of the variety that one has, the buds can take much colder temperatures. Endless Summer's flower buds can withstand being unprotected thru sub-zero temperatures with no problems. The concern with potted plants is actually the roots, which are not well shielded from the cold tempratures (not as well as your on the ground hydrangeas for example).

I would move them into a garage instead of into a room. Interior rooms are generally not very good places because the shrubs get dried out easier when the heater kicks in. I prefer to expose the shrubs to some cold and less light in the garage.

Do not be too concerned making potted plants go dormant as soon as the on ground hydrangeas. Hydrangeas grown in warmer locations such as Orlando, Florida (for example) will not go dormant much. It would be nice if they were to go dormant since this will make them sturdier should temperatures go down a lot but you are basically protecting them now by moving them into the garage or other protected area.

[msalcido]

Thanks Luis as always. I had moved them back outside on Saturday and then back in yesterday but put them in the garage. Another question - once temps get back up and aren't going into the 20's do I take them back out or just leave in the garage until Spring?

Thanks again!

[luis_pr]

Winter temperatures over here tend to bounce all over the map. It would not surprise me to see them go back to the upper 60s soon. So you can do either: (1) bring them inside and take them out when it is above freezing at night or (2) bring them inside until Spring. I have done both. But it gets tiresome when the temps fluctuate too much so I look at the 10-day forecast in www.weather.com in order to decide. Either choice is correct.

If you lived further up north, you would have a similar problem. For example... the plant has not gone dormant; winter is close and you find yourself checking the nightime forecasts often, trying to decide when to winter protect. But then you look at the plant and the leaves are still green... it looks weird to winter protect a shrub that is not dormant. As the cold temps get closer, you end up winter protecting.

That does not kill or harm the plant. It just feels and looks weird. It is... bedtime for the hydrangeas.

[msalcido]

makes alot sense really. I think I will leave them out until we get into our first night of the 20's. After I'm leaving in the garage. I was going to put up the pop up greenhouse but decided it's too much hassle for the few potted hydrangeas. I think them being outside this week and until it gets colder will help.

I really appreciate all of your assistance!


Thanks!

[luis_pr]

You're welcome. I just checked the forecast and we will have freezing low in the 30s on Sat/Sun but nothing else within the next 10 days.

[luis_pr]

Remember to water the potted plants. You can insert a finger a feel how dry/wet the soil is.

[msalcido]

Yep - have been. I left them outside until Saturday during the day since it was going to drop into the 20's. If you don't think there is any harm in moving them back and forth, I think I will do that. It's supposed to get back into the 60's today and the lows in the 40's.

Thanks for all your help!

[luis_pr]

Yes, it was only supposed to go down to 29. I left all my potted shrubs inside. Funny though, the potted hydrangea lost its leaves. The hydrangeas on the ground have yet to loose any leaves. This is opposite to what your hydrangeas are doing!

[msalcido]

I moved them all back outside and they are still as green as the first day I bought them. They have been out all week since last Saturday. It's odd how some react differently than others. I wonder why all my potted ones are not dropping leaves and the in ground ones are and yours are opposite. We are not even that far away from each other. I'm in Coppell so maybe 15-20 minutes from you - Weird!

[luis_pr]

I am not surprised that some are still green. I have had some stay green until really late December. Our up-down temperatures do not let the plants go dormant early. I compare it to trying to sleep besides someone who snores! You wake up. Fall asleep a little. Wake up again. Hee hee hee!

[msalcido]

LOL...I know that feeling!

On some of the potted ones, the leaves are turning yellow and falling off. I can see where the stems are turning "woody". With the temps we have been having they won't go dormant until March! LOL.

Hope all is well. Happy Holidays!

[msalcido]

OK - so now what? The hydrangeas have been covered in ice since Tuesday, and now ice and snow from last night. I did mulch them, but will this be enough to protect them?

[luis_pr]

Normally, that should do it. Varieties that are hardy to Zone 8 should be able to handle the weather on their own without any protection whatsoever.

The problem that we have is the temperatures. The merry-go-round that the shrubs get here can confuse them and, if we get periods of warmth followed by freezing cold temps, the plants could loose their flower buds resulting in no early Spring blooms. Protecting the shrubs with leaves (usually not done here but common in colder zones) would be the only solution.

This scenario happened once in the last 10 years or so. The shrubs were not hurt but flower production was negligible, especially in those that bloom on old wood; remontant ones like Endless Summers skipped blooming early and bloomed in late Spring instead.

[msalcido]

completely missed this! Yeah, you were correct that did the trick. They all have little buds all over them. I thought for sure the ice/snow was going to kill them. I did put more mulch on them the day before the second snow fall just to take extra precaution.

I'm so ready for Spring and blooms!

[luis_pr]

I hope you were not ill. There seems to be a flu-like disease going around at work in the western side of the Metroplex. I suggest getting the flu vaccine if you have not taken it yet. It may lessen the missery at worst. A bunch of people are absent and many cough so hard that you would expect that a fur ball was going to pop at any time! You could almost see (hear?) "the wave" action at the Ballpark being done with peole coughing. Near the end of the disease, you are stuck with a lesser cough until it passes. In my cubicle of 8 persons, we have been working with only 2 or 3 people since Monday. The hydrangeas can wait.

[msalcido]

Thanks - no not ill thankfully! Just been busy!

We purchased a new house on Lake Holbrook (east Tx by Mineola) and trying to get that place in order.

I'm very excited because I have plenty of space for new hydrangeas. I'm just conflicted on what kind! I guess that is a good problem to have.

My only concern is, I'm only out there on the weekends. Do you think watering every weekend during the summer would suffice? Since we are on the lake the soil is very loamy and there is alot of moisture but I'm still worried about watering.

Let me know your thoughts.

Hope you are well.

[luis_pr]

Touch question. You say there is a lot of moisture now. Are the moisture conditions the same during the hot summer months? It is correct to be concerned since I always water twice a week during the hot summer months. The hot temperatures are an issue but sometimes you have to deal with hot drying winds.

You can try to compensate for these two problems by planting in North or East facing sites that get shade starting early in the morning, like 10am & by using lots of mulch, at least 4"; this would preserve soil moisture during the windy summer months and during the times that you will not be there.

Use of oakleaf hydrangas might be recommended as they are drought resistant, more so than macrophyllas but they cannot tolerate wet feet so just make sure the location drains well. Visiting neighbors who have hydrangeas might be called for; ask the neighbors if watering only on weekends is enough for them.

In East Texas, visit the Ruby M. Mize Azalea Garden in Stephen F. Austin State University in Nacogdoches. It has hundreds of hydrangea varieties. Ask for their opinion about watering only during the weekends.

Any chance that a neighbor or their children can assist during the weekdays? You may have to experiment with a limited number of shrubs to see what happens. I would look around other nearby houses for use of hydrangeas, azaleas and camellias.