Ornamentals

(November 2011)

I love gardenias and last year I bought a plant and planted it outdoors. It lived until frost and then it died back to the ground. I just left it alone and it came back out slowly but it never bloomed. This year I bought one that says frost free. I planted this one in a pot. Should I leave this one in the pot outside, bring it inside or plant it in the ground? Also, what about the one I bought last year, just leave it alone?

Many gardenias took a hit with our cold winter weather last season. While most didn't die, if they get frozen back, you do lose the blooms for that season. Gardenias have flower buds set before they head into winter. They are much hardier planted in the ground than planted in containers. Elevated soil in a small pot gets colder than ground soil. At this stage, the one that is in a pot, I would suggest either moving it into a garage or storage area to prevent it freezing and then plant it in the ground next spring. Planting now is not going to allow much time for the roots to establish before winter sets in. The plant that is already in the ground, leave it alone and hope it survives the winter better this year.

I have two five foot tall hibiscus plants which I have brought inside. Their trunks are composed of 3 to 4 intertwined branches and they seem to be healthy. A recent article of yours said these should be cut back 50% when I put them back out in the spring. My plants seem more like a tree than a plant. Should they also be cut back this severely or somewhat less than your suggestion?

Tropical hibiscus plants bloom on new growth. If you don’t cut them back, they don’t grow as quickly and you don’t get as many flowers. Since yours have braided trunks and have been tree-formed, you will not cut into the trunks, but you will want to severely cut the network of branches at the top of the braided trunk. I would also suggest repotting it when moving it back outside next spring. Both pruning and repotting should encourage new top growth, which should result in constant flowers. Don’t forget to fertilize at least monthly once outdoors as well.

We have a deck that is approximately 20 feet above ground. My husband had an arbor built above the railing. He has jasmine honeysuckle growing from 8 large pots sitting on the deck. The plants have been growing for about 4 years and some of them have made it to the top of the arbor which is what we want. However, each year we usually have 1 or 2 plants that die back somewhat and have to start over. I have been thinking that we need to protect the plants from the cold since they are sitting above ground level. Do you have any suggestions as to how this can be done?

If the plants are dying back to the pot, but then resprouting, there is enough protection in the size of the containers to protect the root system. What is getting nipped is top growth, which will be trickier to protect. Make sure there is ample moisture in the soil prior to a heavy frost, since dry plants are more susceptible to winter cold. You could also wrap the vines loosely with burlap, sheets, etc. when temperatures are predicted below 15 degrees. You can leave them covered for extended periods without any problems to the plant. Just make sure it isn’t too tight, and be aware of weight issues should we have winter precipitation. Can the arbor support the added weight of wet fabric?

(December 2011)

I have giant elephant ears in a huge pot outside and I'm scared for them with the cold. Do I let them die down and dig up and store; or I could move them to my covered porch for the winter? It's cold for them!

For the most part, elephant ears are winter hardy outdoors throughout Arkansas, but there are some varieties that are a little less hardy. The fact that you have them in containers, also lowers their hardiness, since soil in elevated containers is going to get colder. If you can move the pot, I would leave them in the container and store the container in the garage, storage shed or porch. If the porch is in use and visible, they won’t be attractive so you may want to store them elsewhere. If the container is too large to move, you can dig them up now that they are dormant, allow them to dry and then store in a cool spot in a box with shredded paper, shipping peanuts or dry peat moss until spring planting

I have two hibiscus plants in pots that I have brought in to the house for the winter. When should I prune these? How much should they be pruned and should I fertilize them?

I would suggest pruning them back by at least half in late February through mid March. You could also wait until you move them back outside, but then the recovery could be a bit slower. Usually by late February, the day length is getting longer and the plants have gotten used to indoor conditions, and they begin to put on new growth. A light application of fertilizer can be put on when you see the new growth. Wait until April to move them outdoors, and then fertilize every two weeks or so. They bloom on new growth, so you need to encourage that by repotting, fertilizing and cutting off old wood.

(Oct. 2010)

I live in Lonoke County and it is bone dry. I have expensively watered lawn, shrubbery and flowers all summer just to keep them alive. Now we are almost through October and I can’t tell if things are turning brown because of the time of year or the drought. How long should I keep watering?

Although some parts of the state have gotten some showers, they were not universal across the state, and even where they did fall, it wasn’t enough to make up for the deficits we are experiencing. Just because the weather has turned cool does not mean we can stop watering. I have had so many gardeners tell me they are giving up, and now is NOT the time to do so. If you have watered all summer, why stop now? Many plants have set flower buds, some are shutting down early, but there still needs to be ample moisture in the plant for it to survive the winter, and to protect the flower buds. We may not have to water daily now, but you still want to apply at least an inch of water per week unless we have rain. Once a killing frost occurs, weekly watering may not be necessary, but if the drought continues into the winter, you will need to water occasionally even when it is cold. Pay particular attention to containerized plants, and when temperatures are going to plummet. Moisture in the ground and thus in the plants acts as a barrier for the foliage and can help protect them. When plants are too dry, they will experience more winter burn.

I purchased a Tecoma stans var. angustifolia plant early in the summer of this year and it is currently still in the original pot. It is about 4 feet tall and a serious and beautiful bloomer. I am not sure how to take care of it this winter so I can continue with it in the spring. Should I ground plant it or leave it in its pot.

Tecoma stans var. angustifolia is a more compact version of the Esperanza or Tecoma stans. This plant is an outstanding bloomer in full sun all summer long and it is still going strong. While Tecoma stans is considered hardy to zone 8, the angustifolia form is listed as hardy in zone 7 (which is what central Arkansas is). I would still question its winter hardiness in a container, but if you want to plant it outdoors next spring and get it established, it should overwinter. For this winter, you will probably want to move the pot into the garage or crawl space for winter hardiness.

(Sept. 2010)

It looks like I may have "killed" my asparagus fern. I have had it for 29 years and it was beautiful. It was in a pot on my porch and had kept it watered well and it was doing good. Then all of a sudden it turned brown and is dying. I thought back and the only thing I can think of that I did - was, and this is dumb, I watered it with some vinegar water. I had always heard that ferns like acid soil - so thought I would give it some - Evidently Wrong!!! Do you think that I could cut it all back and keep it watered and fertilized - or is it gone????

I hope it isn't totally dead, but never use vinegar on a plant you want to live. Vinegar is often touted as an organic weed killer—and it is non-selective, meaning it doesn’t treat the good plants any differently than the bad. Regular household vinegar is a 5% acetic acid concentration. Acetic acid is what has the potential to kill vegetation because it draws moisture out of the leaf. Research is ongoing as to the effectiveness of vinegar as a non-selective weed killer, so we are not recommending it at this time, but so far, they have found that strong concentrations of acetic acid are needed to kill tougher weeds, but any amount can burn a plant. Since you did dilute your solution, it should be even less than 5%, so hopefully you just burned the plant and there is still life left. Cut off the damaged parts, and put the plant in your sink or shower and let water run through it to leach out any residue. If the plant is not totally dead, it should begin to sprout back out.

(March 2010)

I have a neighbor that needs some help with her nine window boxes. Her window boxes are 36" long, 7 1/2 " wide and 6 " deep, and they have a nice layer of moss all around, and no plastic liner. There are 4 on the first floor and 5 on the second. They get some morning sun, the 4 on the right more - maybe 4 hours, and the 5 on the left maybe 2-3 hours. Watering is not a problem, but her house is a dark red. Light pinks, yellows, white and any shade of green, especially the silver ones would look good. She would like a cascading effect on the top 5 as they are so high up. Would perennials work? That way she wouldn’t have to replant every year. Any suggestions you have would be wonderful.

There are two reasons I would probably opt for more annuals than perennials. First, I wonder how long perennials would last in these window boxes. The soil temperature will get much colder in these moss lined wire containers than in the ground, the containers aren't that large, so the volume of soil is smaller, and they will be elevated, so my guess is that most perennials would freeze or at least go totally dormant during the winter. Another downside for flower potential, is that perennials have a defined season of bloom and then they have a period of just green growth. Do you want them to have color in the winter months as well? How awful would it be to use annuals? For the summer season, Silver falls dichondra would be fantastic in them as would the sweet potato vine--there is a pink and white variegated one, or even the Blackie would look good. If you want to try a perennial, try variegated Vinca major or the variegated needlepoint ivy. Creeping jenny would also be nice, but the bright yellow of the foliage might clash--you may want to go with the green one. For color in the pots that is more upright, try the Zahara zinnias, bubblegum pink petunias or angelonia. These are all annuals, but give you way more color in a season than perennials would. Some of the smaller ornamental grasses may also be a perennial option for filler.

(July 2010)

I have some petunias planted in urns and a hanging basket. They all have grown over the edges and are hanging down, which would be beautiful but they are looking ugly and woody. Is it the hot weather? Should I trim them back, if so how much?

If the hanging baskets aren't large, this often happens to petunias with hot weather. I think they often do better for home gardeners in the ground. They need a lot of fertilizer in containers to keep full and healthy. Petunias are heavy feeders in any situation, but we water pots so much that we leach out the nutrition quickly. Weekly applications of a water soluble fertilizer are needed for petunias in pots to look good. Cut them back by half or if the ends look good, add some more plants to the top of the container to fill in there.

(April 2008)

I have two bougainvillea plants that I have had a couple of years. I bring them in each fall. I was wondering when it would be safe to put them outside this year. Also I am trying to stake them so they will look like a tree instead of a bush. Do you have any suggestions?

I think it is a good idea to wait until mid to late April before moving any tropical plants outdoors. This just guarantees that a late frost won’t hit them—think back to last year!! Bougainvilleas usually bloom better if they are slightly pot-bound, so don’t give them too much container space or you may get more foliage than flowers. To train them into a standard takes time and patience. You would need some form of stake to get the trunk established, then start pruning the top at a height where you want the bush to begin. Be careful, since the stems do have thorns on them.

(June 2008)

I saw on TV last fall that you can plant tulip bulbs in dirt in pots. I thought that was a neat idea and I did that. I had tulips blooming everywhere in them in April/May. What should I do with them now? I potted geraniums and other plants on top of them for the summer. Is that okay.

Tulips are not one of our best repeat bloomers when they are planted in the ground, so I am not going to hold my breath as to how well they will come back in your containers. The main concern I have is moisture. Tulips are best planted deep in the ground which keeps them drier in the summer months. In containers with plants on top, you will be doing regular watering and the bulbs are going to stay awfully moist. If you try this again in the future, consider letting the foliage grow for the requisite six to eight weeks after flowering, then lift and dry the bulbs for replanting the next fall. For best show with spring tulips it is often best to use new bulbs every season anyway.

(October 2005)

I recently went to Maine and brought back a Limelight Hydrangea that grows to be trees in Maine! It is in a 10 inch pot and is about two feet tall! My question is should I plant it or keep in the pot inside? I thought these were so pretty in Maine; they have huge blooms on them and grow to be 10 to 15 ft tall there!

The ‘Limelight’ hydrangea is a cultivar of the Hydrangea paniculata or panicle hydrangea. These plants can grow quite large and bloom on the new growth, so you don’t have to worry about winter damaging the flowers. I would definitely plant the shrub in the ground now. It will fare much better in the soil than in a container indoors and should have no problems with winter damage. Amend the soil with organic matter, and mulch. Water periodically, even in the winter if it gets dry. Planting now should give you a stronger root system next spring and a stronger plant for the growing season. The flowers on this cultivar are reputed to be lime green, however they often appear more white than green in our climate. Either way it makes a pretty bush, growing ten feet or more in height and five to six feet wide.

(Dec. 2009)

About two weeks ago I planted Dutch iris bulbs and muscari bulbs in big pots. They are coming up now, so I won't have them in the spring like I had planned. Is there something I can do to protect and prolong their growth? Should I have waited to plant them after a frost?

It is not unusual to see bulb foliage up this time of year, particularly grape hyacinth or muscari bulbs. They start growing in the fall every year and still have spring blooms. Add a little extra mulch around them but don’t worry. They are cold tolerant. As for the Dutch iris, I am surprised they sprouted that fast, but you should just have foliage and no flower buds yet, so again, you should still have spring blooms.

(February 2010)

(October 2007)

I read your column on a regular basis and find many of your tips very helpful. In some of your answers about over-wintering plants, you mention "put them under the house". What do you mean by this? Would under the deck (and off the ground) accomplish the same thing? I have three lush and beautiful Mandevillas that I do not have room for in my garage.

I guess I should have explained this better. When I say storing under the house, I mean in a crawl space area or unheated basement. If you put them under your deck you would not protect them from freezing temperatures and I am afraid you would lose the mandevillas. Crawl spaces typically have enough residual heat from the house above to protect the plants enough. They don't get light or care during the winter so they aren't lush beautiful plants when they come out but they are alive. Prune the plants hard when you bring them back out and repot and they should be good to go for another season.

I have plants (in pots) that will need to come inside for the winter. I don't want to bring in a lot of bugs in the house. What do you suggest that I spray them with before bring them inside?

Clean the outside of the containers and lightly spray the foliage with insecticidal soap. You can also water the plants and then drench the soil lightly with insecticidal soap as well. You want to make sure there is ample soil moisture before using insecticides to prevent burning the foliage.

(April 2006)

I would like to plant some pink and purple annual flowers in some containers on my deck. The containers are quite large and the area gets almost no shade the entire afternoon. What are some good plant combinations that will allow me to have non-stop color all summer?

When we design container gardens it is always best to have three different forms in the pot - something with some height, something filling, and something cascading. For your taller plant, consider one of the beautiful pink mandevillas. It does need some support, but it will grow quite tall and bloom non-stop all summer long. A nice fill plant could be pink or purple pentas and the cascading flower could be trailing verbena or wave petunia - in pink or purple. For some contrast, add some asparagus ferns, dusty miller or Artemisia. Regular watering and fertilization and you should be good to go all summer long.

(March 2006)

My neighbor was recently in the hospital where she received a big, gorgeous, gardenia plant. How does one take care of it? Can it be put outside? What kind of care does it need? Also it's getting yellow leaves. Please help, it's so fragrant and beautiful, it would be a shame to see it die.

Enjoy the plant inside for now. This gardenia should be treated as a houseplant for another few weeks, since it was forced into bloom in a warm greenhouse. By mid April it can be safely moved outdoors. If you live in central or south Arkansas, the plant can be put in the ground as a permanent shrub. Plant it on the east or north side of the house where it gets bright light in the morning. If you are live in the northern counties, it will not survive outdoors year-round, but it does make a great container plant. Don't over water it indoors -- allow it to dry out slightly between watering. Give the plant bright light while it is inside and it should make it through until it is safe to move outdoors.

(March 2005)

I have an oleander tree (about 6 ft tall now) that I move outside at the end of March every year in Fayetteville. I have over-wintered it in the garage (it has done fine) and am wondering how I prune this plant to encourage flowering. The first year it flowered nicely. It gets about 4 hours of direct sunlight and about 4 hours of dappled sunlight. I have never pruned except some suckers and inside pointing twigs. Does it bloom on new growth or old growth? This will be the 4th year and it bloomed a little last year but less and less every year. Does it need to be fertilized? Help.

It does bloom on the new growth, so if you are not pruning it and it is containerized, it is probably maintaining a constant size, and flowering will be somewhat limited. Also, the more sunlight it gets, the better it will bloom. Repot it this spring when you move it out--either putting it in a larger container, or replacing the old soil with fresh and breaking up any root-bound conditions. Then prune it back by one third or more. Fertilize monthly, and try to increase the light if you can. Hopefully, you will see an abundance of flowers this summer.

(November 20050

I live in NW Arkansas and I have several large containers outside on my deck that I would like winter color in. What options do I have for a shade garden? I have many large oak trees surrounding my house. I have five large containers and I would like plants that would take our winter.

You might try planting bulbs further down in the containers and then lining the tops with pansies, violas and parsley. If your shade is primarily from deciduous trees, you typically have enough sunlight through the winter months to have annual color. New bulbs can be planted every year, since they have flowers set when you purchase them. They set their energy in the 6 weeks after bloom for next season’s flowers. You can reuse them or buy new. Make sure you do water the containers even in the dead of winter—especially prior to a really cold snap. The larger the container, the more winter hardy your plants will be. Small containers dry out quickly, and the soil gets much colder.

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