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Archive for the ‘Ask A Master Gardener’ Category

How To Care For Fuchsia Plants Over The Winter

October 28th, 2013

How to overwinter your fuchsia plantsHi. I bought several fuchsia starts this spring and they have been feeding our local hummingbirds all summer.

What is the best way to treat these fuchsias over the winter? When I bring them in, should I cut them back? How often should I water them? Please help, Diana

Answer: Holding over what are annuals in your area is always tricky but it is possible with many of them if you remember you have to simulate their growing habits. The typical home in winter is very dry and warm, so you will want to increase the humidity around the plant. The days are shorter, and usually lack sunshine, so you might need to add artificial lighting, as well.  Fuchsia would need to come in before the first frost in your area. Pruning back by at least a third would be best. Be sure to treat the plant for any pests that might be traveling indoors. The easiest way is to make a mild mixture of dish soap and water, spray the plant liberally, and rinse with the hose. Place the plant in a window with bright light but not direct sun, away from drafts or furnace vents. Slow down the watering by letting it almost completely dry before watering again. The plant may go into semi-dormancy and drop leaves. If it does, just let it rest for a while and don’t water as often. In March, start watering with a very mild fertilizer, and you should start seeing new growth on the plant. You can move it outside on warm days but if the nights are below the upper 40s, you need to bring it back inside or just wait until your last frost date to take it outside. It will take it a while to catch back up to those that are being offered for salebut it should.

I personally hold over a significant number of annuals through the winter and I have mixed success every year. Some things do quite well; others struggle or succumb, but I am always happy to have a few plants to begin the spring season with.

Remember, you may still have hummingbirds traveling after you bring in your Fuchsia, so leave some feeders out for a while until they’ve all made the migration south.

Happy winter gardening,

Karen

Why Are My Hydrangea Not Blooming?

September 12th, 2013

Varigated_Hydrangea_LeavesVariegated hydrangea, have had 5 years or so. Does not bloom. Have kept old wood, no bloom; cut off old wood, no bloom. Gets morning sun, shade in afternoon.  Soil is clay, but amended, and has good drainage. Very nice plant, lovely leaves, just no flowers. Thanks, Rose

Answer: Rose, there are several varieties of variegated hydrangea; some are two-color and some are three, but none of them are big bloomers, especially anywhere in Zones 5 or 6. They were developed primarily for the interesting foliage and not for their blooms. That said, mine did bloom a few years ago when we had an unusually mild winter here in the Midwest and the blooms are nice. It sounds like you have done most of the appropriate things to encourage it to bloom. Besides adding more compost to the soil around it, you might also add some Espoma Flower-tone to the soil this fall and again very early spring when buds are starting to form. This is also when you would add any soil acidifier if you want the blooms to be blue. I like the Espoma “tone” fertilizers because they are very mild and you can add significant amounts without damaging or burning the plant. You might also try wrapping it in the late winter, after December, to protect against the late spring frost. There are wraps out there that are supposed to zone up the plant by one climate zone. The down side with this method is getting an early warming spell and the plants getting too warm, then frost again. You could try just using burlap, which will protect the plant but it will still allow the cold and warming temperatures.

I’ve learned to enjoy mine for its foliage, and if I get blooms it’s a bonus.

Happy gardening,  Karen

Why Are My Delphinium Plants Not Growing?

July 15th, 2013

How to grow delphinium plantsNo fault of yours, but this is the fifth Delphinium I have planted in the past three summers and it didn’t make it past a week in the ground. Must be something in my soil, because everything else is growing beautifully. The first year, two flowered and didn’t return. Second and this year they just died within a short period. Maybe they don’t like Long Island.

Answer: Dear Long Islander, Growing Delphiniums can be a challenge even for the advanced gardener. They are a finicky, short-lived perennial with flower stalks up to six feet tall sporting blooms ranging from midnight to royal to sky blue, and even some in pinks and white. They are often called Larkspur, a member of the Ranunculaceae family.  They prefer a climate that has cool and moist summers, not the hot, dry summers we have been experiencing lately. The soil needs to be moist, well-drained, and not heavy clay, and they want full sun to light shade. It’s often best to put them in a raised bed. When planting them, dig a hole that is at least twice the size of the root ball, and mix in compost to help keep the soil well drained. If you can get them established, then you will want to cut the stems back after the killing frost to an inch or so above the soil line. Divide plants every three to four years.  Good luck with your flowers.

Which Rosemary Should I Grow?

June 17th, 2013

Rosemary plant growing in the gardenHello Karen: I live in Atlanta.  I am going to plant miniature boxwoods.  Could you help me with the rosemary? Thank you, Dorothy

Answer: Dorothy, Since I don’t know what Zone you are in, I want to first say that most Rosemary is only hardy to Zone 7 or Zone 8. Please check each plant information section if you are wanting these to be perennial.

I am also thinking your boxwoods range from 24″ to 36″ tall, so you are needing a shrub version of the Rosemary.

We have several varieties available. The ones that would make the best hedge would be: Rosemary Herb PlantRosemary-Arp Herb PlantRosemary-Barbeque Herb PlantRosemary-Hill Hardy Herb PlantRosemary-Shady Acres Herb PlantRosemary-Taurentius Herb Plant; or Rosemary-Tuscan Blue Herb Plant.

Each variety has its own unique fragrance and growing characteristics as described in the plant information section. If you can’t decide, choose a couple of varieties and see which does the best in your location.

Happy growing,  Karen

What Flowers Do Not Need A Lot Of Sun?

April 13th, 2013

Hanging basket of flowers that only need part sun to growI have flower baskets that face east, so not much sun.  What do you recommend for a flower that does not need a lot of sun and has a vine or drape to it?  I’m in N.C.  Thanks. Pat J.

Answer: If you are limited on sun, generally less than 6 hours per day, there are some really nice colorful foliage plants available these days and they can be more dependable than flowers! There are several options in our Annuals section that would make great shade containers.

I garden with a lot of shade, and some of my favorites for sun/part share are: Abutilon; Bacopa especially the Snowtopia because it’s a nice trailing variety; any of the Begoniathe old standard Angel or Dragon Wing series are always great, but the newer Bonfire series are spectacular as well; and of course the Fuchsias are marvelous. One newer introduction, a variety of  Euphorbia, has tiny nonstop blooms that look a lot like Baby’s Breath and it makes a great filler plant or an entire basket on its own! Impatiens are a natural for the shade, and there is a new variety, Torenia, that will also tolerate some shade.

For pure leaf interest don’t forget about the Sweet Potato Vines. Coleus are also perfect for brightening up shady areas, but some can get quite large, so you would want to check their mature size before considering them for a container. Plectranthus has some interesting leaf texture, as does Persian Shield. For tall, spiky interest use a Dracaena.

Don’t be afraid to look at some of the Perennials, as well. There are many that make terrific options for containers. Start with Hosta,  Heuchera and, Hedera. At the end of the season just put them into the ground to overwinter.

Happy shoppingand happy gardening!
Karen

How Should I Start Lemongrass

April 5th, 2013

Lemon Grass Plant Growig In A ContainerI would like several potted lemon grass plants for my patio. Should I start indoors now? How long will they take to grow 5-6 feet tall? Should I buy the stalks and start myself or just get the plants at a greenhouse? Thanks, Julie M.

Answer: You can start the lemongrass indoors from cuttings.  If you search our blog you will find several articles talking about this.  We do sell healthy starter plants, and these will be ready to go outside as soon as you’ve passed your last frost date. You are in Zone 5a, which means that date should be somewhere mid- to late May. If the plants are growing in pots they are not likely to reach their full size of six feet but should grow tall and full by the end of your growing season. Plants can be brought inside and overwintered as well, if you have a sunny, draft-free location.

Happy gardening!

Karen

Need Help Growing Lemongrass

February 28th, 2013

growing_lemongrassI’ve planted some lemongrass stalks that I bought and rooted in water. When they had a strong root system I planted them in a pot and put them on a southwest window sill. I’ve tried to maintain moisture and fertilized, but unfortunately not only have they not grown but they are slowly withering away. I hope you can help me figure out what I can do to keep them alive and hopefully get them to grow into a decent plant. I live in the south of Spain where the climate is warm and dry most of the year, but I have to keep delicate plants indoors in winter as we are at the foot of the Sierra Nevada mountains and get frosts. Thanks, Diane

Answer: It’s always difficult to fully diagnose the exact cause of plant failure, but here are some suggestions to try again.

I see about a 50/50 rate of suggestion as to starting lemongrass in water or soil. Most who recommend water rooting do suggest to transplant directly to soil. However, the cell structure of water roots is different from that of soil roots, so it’s imperative to keep the soil generously moist in the early days of transplanting. You can even cover the plant with a plastic bag to seal in the humidity. Another method to move the plant to soil is to daily add soil to the water to allow the roots to transition in cell structure.

You might also just try using soil to start the lemon grass. Just make sure it’s well draining. You will want to cover the pots to keep the moisture in.

Keeping the plant in a warm sunny spot is important, as well. If there is a draft from the window, you might try moving it to a warmer spot and make sure it’s getting as much full sun as possible.

Do not fertilize the starts. Let them show active growth before applying any type of fertilizer. Most plants don’t need a lot of fertilizer except when blooming or fruiting, to help boost that process.

Give it another try, and maybe test both methods and see which works best for your conditons.

Happy gardening,

Karen

Frost Protection Blankets and Wind Chill

February 21st, 2013

Dear Master Gardener, Can you tell me how wind chill affects the plants under a frost blanket? For instance, if I am using a 24-degree frost blanket for protection and the temp is 28, however we are having winds at 25 mph, what effect does that have under the blanket? Or how much temperature protection will my plants lose due to windchill? Thank you so much, Denise

Frost Blanket covering plants

Answer: Denise, That’s an interesting question. Frost blankets will effectively “zone up” your area one zone. It’s like a coat for your plants. However in the case of wind chill, only humans are affected by this. Wind chill estimates the amount of heat loss from warm-blooded creatures as the wind passes over exposed areas of the body. Plants do not generate heat, so essentially they are not directly affected by wind, and if under cover they would not be affected by the wind.

What can be more detrimental to your plants is the dew point. This is the temperature where air reaches water saturation. There are several scientific methods of calculating this and the numerous effects it has on vegetation. Water vapor helps to slow the temperature fall. With a high dew point, radiant heat losses are slowed, but if the dew point is low, the temps may fall rapidly. Think of how fog in an evening will make it warmer.

You can add some forms of mild heat under the frost blankets, like Christmas lights or milk jugs of water that have absorbed the sun during the day.

Hope that helpsand happy gardening.

Karen

Will This Keep My Plants Alive During The Winter?

November 15th, 2012

I have a metal frame left standing on my south deck which is 10′ X 10′. If I wrapped and covered this with thick plastic sheeting, would it keep my plants alive through the winter? Thank you, Cecile.

Answer: Well, this will help protect some plants during your winter season, but you will need to know the plants’ Hardiness Zone. Your location is Zone 8a. Typically, adding one layer of protection, like a heavy plastic sheeting or row cover fabric, will add one Zone in protection, so theoretically inside would be Zone 9, and you can add an additional cover or protection inside for an additional Zone. You begin to get a significantly diminished light source with the second layer, so be selective on what plants you are protecting. Make sure that the plastic and structure are securely fastened down, as this will be highly susceptible to high winds and could easily blow apart, exposing the plants to weather they are unaccustomed to.  A UL-approved heater for wet locations could also be added. Just make sure it’s in a properly grounded outlet. I’ve also used a remote thermometer so I can keep track of night temps in my temporary greenhouse, and you want to make sure that there is a way to vent it on sunny days, as the temps can climb rapidly.

Do some reading on greenhouses and cold frames to see how they are best secured to a structure. Also make sure to research the Zone of the plants you are trying to overwinter to see what they like. Some tropicals can be put into dormancy and overwintered in a basement or garage that stays above 45 degrees, much easier than worrying about them outside!

Good luck with your cold frame.

Karen

Why Are My Pole Beans Not Setting Blossoms?

August 20th, 2012

IPole beans growing up a pole in the garden have planted Blue Lake Pole Beans. The site gets a lot of sun and I water on the base every day. I have beautiful plants but no blossums. Another type of pole bean, Burpee I think, has produced blossoms in the same vacinity. It has been almost two months and the plants themselves are very robust but no indication of flowering or beans. Please advise.   Bruce S.

Answer: I cannot give you a definitive answer as to why one variety did well and one did not, but I can give you some possible reasons.

In general, Blue Lake Pole beans need the following conditions:

First, they do not like to have too much nitrogen in the soil. The nitrogen makes them nice and leafy but inhibits blossom production. Since beans go thru a process of “nitrogen fixation” where they produce nitrogen in their root systems if the soil is already nitrogen rich from compost, then it could be the cause of no blooms. Test your soil first to determine nutrient levels. Heavy, clay soils will hold a lot more nitrogen than sandy soils where the nutrients tend to leach out.

Second, is the weather. Beans like the temps in the 70- to 80-degree range and if the temps are consistently over 85, then the blossoms will not develop. Hot dry winds will also aggravate the situation. Temperatures under 70 will cause the plant to not even attempt flowering. East Coast temps have been pretty high, so this could be a problem. It’s possible the other variety is more tolerant of such conditions.

Another thing to consider is fluctuations in soil moisture. The Midwest is experiencing a severe drought, so if you are having the same conditions, then that combined with the heat could be causing much stress on the plant. Blossom drop always occurs under stress conditions.

Also monitor for signs of any kind of disease.

Check the ripen time: Blue Lakes are typically around 60 days to harvest. They could be waiting for some cooler weather, as well.

I hope that gives you some ideas of things to look for. Remember, you could start some new plants and maybe get a late harvest out of them, when hopefully the weather is more cooperative for growing and fruit production.

Good luck with your garden,

Karen

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