Garden Answers
Perennials
When should I prune my flowering perennials?
How do I get my perennial beds ready for the winter?
How do you deadhead plants like Gayfeathers?
Can I transplant a peony this fall or wait until spring?
What is "dividing" of irises and daylilies?
Is there a way to safely transplant?
How to care for mums that are planted in containers?
How do I safely transplant perennials that need to be thinned?
Question: When should I prune my flowering perennials and is there a
rule of thumb covering all or most kinds as to how to do it?
Answer: Lots of folks are asking about pruning perennial beds. People
differ about when they like to prune their perennials-some do
it in the fall after the tops have died down. That's what I
do in my yard: it looks a little more tidy through the winter,
and I tend to be a little busy in the spring. It just makes
more sense for me to do it in November when I have the time.
It is, however fine to prune your perennials back anytime now.
There's nothing wrong with letting them go all winter and pruning
them back early in the spring, just be sure to do it before
they start to sprout or you may clip the new growth which can
set the plant back.
The exception to all this are the few perennials that stay
evergreen. Things like Evergreen Candytuft, some Dianthus, and
the like shouldn't be pruned back in the fall. If you need to
cut them back (they don't always need it), do it now.
As to how to do it, all you want to do is to cut off the old,
dead, dried up growth from last year. Just cut it off down low,
one to three inches off the ground. Again, make sure that you're
not cutting any new growth that may be coming up. If there is
some, just cut the plant back a little higher to avoid the new
growth, and be sure to cut them back earlier next year. Hope
this helps.
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Question: How do I get my perennial beds ready for the winter?
Answer: Start out with gauging the moisture of your
perennial beds. As the plants are starting to go dormant, you
can begin to stretch out the time between waterings. Many folks
will have stopped with a regular watering schedule (usually
happens after the irrigation water is turned off), and are relying
on the moisture we've had from recent rains. As it gets dryer
(or if it warms up), you'll need to keep an eye on your perennial
beds and be sure to maintain their moisture. Then you just need
to be patient. I usually wait until things dry up and start
getting brown before I start cutting back anything. Then once
they do, I'll cut them back to the ground. Some folks like to
pull foliage off plants, but if you do, make sure that the foliage
is completely dry and be careful. I don't use this method because
it's too easy to damage the crown, break roots, and cause the
plant to be hurt. There are some evergreen perennials, and those
I just leave alone.
Once you've cut back your perennials, it's good to provide
a light covering of mulch around them. Though most are hardy
here, adding mulch on the ground around your plants will help
to hold in moisture. Winter drought is our biggest problem here
in the valley, and mulching is an easy and economical way to
prevent that. Tuck your plants in, and then just let them rest
for the winter!
Though it's getting a little late, it's still okay to divide
your perennials. If they are looking overgrown or starting to
thin in the middle, those are good indications that they are
ready to be divided. Dig them up, clean them off, cut out any
dead spots, divide them and set them into their new beds.
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Question: How do you deadhead plants like Gayfeathers, Red
Hot Pokers, etc?
Answer: Deadheading perennials is an easy process. All
you're trying to do is to cut off the old, spent flowers. Cut
the flower stalk off down to where there's healthy, strong foliage.
Some perennials don't have foliage on their flowering stalks
(like your Red Hot Poker) and the entire stalk should be removed
down close to the ground. Some perennials bear their flowers
in large clusters. I generally cut off the entire cluster to
make the job simpler and quicker. Deadheading helps keep the
plant looking neat, but it can also extend the bloom season
of your perennials, and most importantly, it results in a stronger,
more vigorous plant. The plant is not putting any energy into
producing seed, so instead it builds itself up resulting in
more flowers next year. Hope this all helps.
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Question: We moved into this house a year ago and I found a peony
trying to bloom under a Cedar tree. This is an old plant, and
I was wondering if I could transplant it this fall or if I should
wait until the spring to do so? Any tips you might have on transplanting
this would be very helpful.
Answer: The best time to transplant Peonies is late
September. There will still be leaves on the plant, and that's
okay. Carefully dig up the mass of fat, fleshy roots in the
soil. You can cut out any dead portions of the root system.
You can also divide the plant if you wish to make more plants
to replant. If you do that, don't cut the plant up into too
small of pieces. At the base of each leaf there should be a
fat reddish-brown bud. Each piece should have at least five
or six buds.
Before you replant them, take advantage of the opportunity
to rework your soil. Mix a good amount of decomposed organic
matter like Peat Moss or Soil Pep into the soil before replanting.
When you replant, be sure to set the root pretty high. I like
to have those buds just below the soil level. A lot of gardening
books will tell you to plant them three, four, or even six or
eight inches deep. Maybe that works elsewhere, but here, if
you plant that deep, the plant will rarely bloom if it even
survives at all. Water them in well after they're planted, and
put down a 3" deep layer of coarse mulch around the plant.
I like to use Bark Chips or Cedar Mulch, but wood chips or straw
will work as well.
I'm a little concerned that you say the plant is trying to
bloom now. When a plant blooms at the wrong time of the year,
it's an indication that the plant is under some stress. It sounds
like your Peony isn't getting enough sun under your Juniper.
I'm assuming that you're planning on moving it to a sunnier
location. It sure would be a lot happier there. Because it's
blooming now, I wouldn't expect much flowering next spring.
The plant will be adjusting to its new environment. It should
bloom fine the following year. Hope this helps.
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Question: My neighbor asked me if I was going to divide my irises and
daylilies. What is she talking about?
Answer: Occasionally dividing and transplanting perennials
keeps them healthy and vigorous, which means better blooming.
A typical perennial gains girth by growing new roots and stems,
usually around the outer perimeter of the plant. Every 3 to
5 years, the clumps get too big for their space. Most perennials
are divided in late September to early October. But now (late
August to early September) is the time to divide your irises
and daylilies.
Start by cutting back the foliage by half and removing any
dead foliage. Carefully dig out the entire clump. Pull or cut
the plants apart, being careful to keep as many roots intact
as possible. Don't let the roots dry out while you're working.
Keep them moist. Before replanting the plants, it's important
to prepare the soil. Work a compost or decomposed organic matter
into the soil to improve its drainage and aeration. Re-space
the plants and plant at the same depth. Water the newly planted
irises and daylilies well. You're done.
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Question: I'm a novice gardener and planted my "pre-planned garden" plants too close and now they are overshadowing each other. Is there a way to safely transplant the plants (Jupiter's Beard, Blue Catmint, and Moonshine Yarrow) that need to be thinned out? This is a new experience for me so any suggestions would be very helpful!
Answer: Late Spring is really not a good time to be transplanting your perennials. They're growing very actively right now, and disturbing them can result in the loss of the plant. However, if you're in danger of losing some anyway because they're being overrun by another plant, go ahead and try it. You may be able to save them. If you feel you do need to transplant anything now, be sure to get a nice big root ball around the plant and get it into the ground immediately (have its new hole already dug out and ready). After it’s planted, soaking it in with a solution of Fertilome Root Stimulator will help improve your plant's chances of survival.
If they're "okay" where they are for now, wait until late September or October to transplant them when they’ll have a much better chance of success. The same planting rules apply (get a big root ball, use the Root Stimulator), but since the plants are entering their dormant stage, they’re more likely to thrive in their new environment.
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Question: How do you care for fall mums that are planted in containers? I would like to keep them for another year.
Answer: Mums are pretty easy to take care of over the winter as long as the pot they're in is big enough. I'd probably like to see them in a pot with a minimum 12" diameter. You could winter them over in a smaller pot, it's just a little harder to do.
The main thing that you have to do over the winter is to occasionally water your plants. Most of our container plant loss is not due to the cold, but due to drought. You probably ought to water the pot once every two to four weeks. Of course the weather will affect your watering schedule. If it's unusually warm and dry, you'll have to water more, if we get a lot of moisture over the winter, you can water less. Moving your pots into a shady spot over the winter will also help to keep them from drying out so quickly.
One last thing to consider is what material the pot is made from. Since you're keeping the soil moist over the winter, it will freeze into ice, which is okay as far as the plant's concerned, but water expands as it freezes and if you have a pot that's too rigid, it can break. Clay or ceramic pots are especially prone to cracking and breaking over the winter, which is why I'd try to avoid using them for your mums. You should be safe keeping your mums in a plastic or wooden container since these materials have the ability to expand a little as the water freezes. There are some "frost proof" clay pots out on the market, but I haven't been too impressed with them yet.
Once the plants have frozen down (around the end of November), cut them back to within 2"-3" of the ground and watch the water!
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Question: I'm a novice gardener and planted my "pre-planned garden" plants too close and now they are overshadowing each other. Is there a way to safely transplant the plants (Jupiter's Beard, Blue Catmint, and Moonshine Yarrow) that need to be thinned out? This is a new experience for me so any suggestions would be very helpful!
Answer: This is really not a good time to be transplanting your perennials. They're growing very actively right now, and disturbing them can result in the loss of the plant. However, if you're in danger of losing some anyway because they're being overrun by another plant, go ahead and try it. You may be able to save them. If you feel you do need to transplant anything now, be sure to get a nice big root ball around the plant and get it into the ground immediately (have its new hole already dug out and ready). After it’s planted, soaking it in with a solution of Fertilome Root Stimulator will help improve your plant's chances of survival.
If they're "okay" where they are for now, wait until late September or October to transplant them when they’ll have a much better chance of success. The same planting rules apply (get a big root ball, use the Root Stimulator), but since the plants are entering their dormant stage, they’re more likely to thrive in their new environment. Hope this helps.
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Question: I have put a 20' long raised flower bed which extends out about 4’ on the west side of my home. It is a DRY BED, and the soil is very poor. I’m wondering what would be the best low-growing flowers or bushes for this spot? I do plan to mulch it.
Answer: Without knowing for certain how low you’d prefer everything to grow, I’ve come up with a few suggestions that may help you. Some, like Butterfly Bush and Russian Sage, can get 4’+ tall but, of course, won’t grow as tall with less water. Here’s the list:
Woody Shrubs:
Gro-Low Fragrant Sumac, Pawnee Buttes Western Sand Cherry, Butterfly Bush, Colorado Manzanita, Parry's Agave, Apache Plume, Mormon Tea, Blue Mormon Tea, Rabbitbrush, Fringed Sage, Broom Snakeweed, Harriman Yucca, and Soapweed Yucca.
Perennials:
Chocolate Flower, Angelita Daisy, Desert Evening Primrose, Desert Four O'clock, Desert Globe Mallow, Desert Marigold, Paper Flower, Firecracker Penstemon, Sand Penstemon, Pineleaf Penstemon, Blanket Flower, Maxmillian Daisy, Blue Flax, Gaura, Ice Plant, Hyssop, Poppy Mallow, Russian Sage, Sea Foam Sage, and Yarrow.
Almost all of these will require some supplemental irrigation. How much and how often you need to water will depend on the amount of soil preparation you do, mulch layers, the weather, the exposure of the bed, etc. Also, some of the above plants will get along will less water and some will need more. I'd guess that you'll need to give the bed a deep soaking once a week to twice a month once the plants are established.
If you get a chance, come by the nursery and take a look at the plants. We also have several books that you can look at to get an idea of what each plant looks like as well as complete descriptions of them.
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