#10 Overwintering Plants
Overwintering plants from the garden is a task the madman readily accepts. He knows that living with plants all winter means he can enjoy them in the summer. Now that the days are definitely getting longer, the madman is thinking, “Can’t wait to get these plants out of here!”
He is starting to get tired of the constant watering and inspection of leaves and stems for uninvited guests. Our garden plants overwinter as our house plants.
A Good Start in Fall Keeps Plants Going
Let’s backtrack to the fall to explain how we got into this perceived mess. The madman is a collector, and his collection of choice is MORE. We don’t just have one citrus plant, we have numerous citrus. We don’t just have one bowl of cactus, we have many. The same goes for brugmansia, passiflora, exotic succulents, rosemary…the list goes on. Ah-h-h-h!
After 40 years of collecting plants we have a lot of them. Granted there has been some attrition over time, however the madman has gotten quite good at propagation and he hates to throw things out (I’m working on that!). And, with his love of seed-starting, well, let’s not go into that. Let’s just say we have a lot of plants to overwinter.
Summer Flowering Bulbs are Easy
Some of the plants are quite easy to overwinter, like the dahlias, cannas, gladiolas, callas, caladium, elephant ears (Colocasia) and voodo lily (Sauromatum venosum). These are all bulbs that are lifted out of the ground after the first frost signals to them that growing season is over and dormancy can begin. We dry the bulbs on old window screens then put them in cardboard boxes filled with shredded paper. Thanks to the threat of identity theft, we have a lot of shredding. The key here is to keep the boxes from freezing or getting damp. We shove them into the back of a cool closet to overwinter.
Preserving Our Favorite Vines
Next up are the Passiflora (passion flowers) because they are the most important to overwinter. We don’t worry about the maypop variety (Passiflora incarnate) because it flourishes in our back bed – so much so that it even comes up throughout the lawn. Our most successful variety is the Passiflora caerulea-we also have a yellow one whose Latin name is now lost. We have tried several different varieties from Logee’s Greenhouse in Danielson, CT, but they don’t always survive and our labeling system isn’t the greatest. Suffice it to say that if it grows like a passiflora, we keep it. We cut the vines back to about 4-5”, then move them to a variety of places – some go to the greenhouse, some go to a west facing second floor bedroom window, others go to the floor in the basement. Wherever there is space. Seems these plants aren’t fussy.
Overwintering More Tender Plants
Brugmansia and Mandeville plants are treated much the same way, although cutback is not quite so severe. We are down to one Mandeville plant, a relatively new addition to our collection. The fact that we have some difficulty with it might explain why master gardener friend Chantal Foster considers the plant an “expensive annual,” and buys a new one every year.
The Passiflora, Brugmansia and Mandeville are joined by Papyrus, Agave and Freesias. When these plants are dormant they do not need to compete with other plants for space under the lights. Note that we do not cut back the agave plants; we just try to avoid their pointy leaf tips.
Cacti and Succulents Were Supposed to be Easy
The madman started growing cactus and succulents years ago because he thought they were easy-pot, bring outside, bring inside, and watch them grow. He was so wrong! Little care, yes; no care, no. Many of these plants spend the summer in the cactus garden which we will discuss in a later post because we are in the process of rebuilding it.
Most of these cactus and succulent plants need some shelter in the winter. They overwinter in the greenhouse, in an east facing bedroom window, under the lights in the basement or the rec room. A few of them even join us in the living room, happy in a south-facing window.
Euphorbias are Temperature Sensitive
Euphorbia, a genus of plants from Africa, will not survive in the greenhouse (which can fall to about 25˚ on a cold winter’s eve)-a painful lesson learned by the madman. These are now quite happy in a bedroom with east and south facing windows. You may have guessed that most of our windows are filled with overwintering plants-my only rule, no cactus in the bedroom!
Because the order of succulents is so large and differentiated, these plants require a variety of conditions so we try to cater to their needs. Sometimes, the madman tries to push the edge of that envelope.
Cactus Care Belongs to the Madman
Which brings us to the cactus. Because of the nasty spines, moving cactus inside is a task that belongs exclusively to the madman. On moving day, he brings the cactus from the cactus garden to the back patio where the soil gets drenched with a mixture of ivory liquid and water (2 tbsp. ivory per 1 gallon of water). This is followed by a quick spray of NEEM oil-an organic, biodegradable, non-toxic insecticide made from the Neem tree. At the end of the day the cactus go to their winter homes in the greenhouse, basement or a south facing window.
Overwintering Annuals and Herbs
With the more exotic plants taken care of, we look at the annuals and herbs to see what comes inside. The only annuals we really care about are those we can use to propagate many plants. This year we are concentrating on begonia, Calibrachoa million bells and geraniums. These do well in the greenhouse.
For herbs, we only overwinter Bay laurel and a couple of different species of rosemary – the rest of the herbs that we use are either perennials or grow easily from seeds. The key to survival for the herbs is plenty of light, cool conditions and a good supply of fresh air.
Living with the Citrus
Going up the scale of difficulty, we come to the citrus. They won’t survive the low light conditions of the basement floor so they either sit under florescent lights or join us in the living areas of the house. More recently the madman has overwintered some of them in the greenhouse. This works as long as he remembers to water them. As much as we love our citrus, they are a pain to overwinter.
As with any plant brought into the house, we make sure there are no stowaways on plants or soil. Any number of insects will jump at the chance to sneak in –or they will simply send in their eggs.
Inspecting Plants for Insects and Disease
In late, September, we bring all the indoor-bound plants to a staging area in the back for final inspection. The citrus and herb plants are lifted from their pots. Roots and pots are examined-millions of eggs and countless ant colonies have been thwarted by this exercise. The pot is cleaned, the roots are trimmed and the plant is repotted followed by any necessary pruning. The soil is drenched with a mixture of ivory liquid and water. We repeat the drenching a week later, and spray the plants with NEEM.
We leave the plants outside to adjust to lower light levels (the area is shaded during the afternoon). By the first frost (which seems to be getting later each year) we have them undercover. Sometimes the cover is a quick tarp until we get them inside.
End of the Persephone Period
Someone has told our plants that the Persephone period has ended and our work has just begun. Our overwintering plants are starting to grow again. And, any critters who have managed to escape our vigilance will start to show themselves over the next few weeks.
Our biggest enemies are scale, aphids and white fly (in the greenhouse). These are all nasty suckers (they are actually sucking insects- we don’t seem to have an issue with chewing insects). The sooner we find them, the easier they are to manage.
Avoiding Scales
Scales are by far the biggest problem, although each year we seem to be getting better. Our first introduction to scales was nasty. We had overwintered three large citrus plants and the madman noticed that the trunk seemed rather knurly. When he ran his finger along the bark, the knurls came off in his hand. We freaked!
The owner of a local nursery calmed us down, gave us directions for hand picking and armed us with a systemic insecticide for use in dire infestations. Our plants survived this brush with the bugs and we learned a good lesson – if we wanted good plants, they required good care. We now spend the winter inspecting leaves, stems and soil of all our plants and have never had such an issue. For the most part, hand picking keeps scales at bay.
Scales, Both Hard and Soft
There are about 1,000 species of scale in North America. Scales are divided into two main families – soft shell and hard shell, but all act about the same. They hatch under the safety of the mothers shell. During the first stage of growth, they crawl away from the maternal site looking for a suitable feeding ground. They insert their straw like mouthpieces into the plant and start stealing nourishment from the plant. Once the scales begin feeding, they will not move from that spot. Scales secret a sticky byproduct affectionately called honeydew. Not only does this make the plant look bad, it is a breeding ground for sooty mold, a black fungus.
If caught early, you can control scale by removing them with a Q-tip dipped in rubbing alcohol. For heavier infestations, spray plants with a horticultural oil which will smother the little monsters. Systemic insecticides should be used only as a last resort since you have to live with these things in the house.
Attacking Aphids
Second up are the aphids, another sucking insect. There are more than 4,000 species of these things. Unfortunately these also produce honeydew which encourages the growth of sooty mold. Again, hand picking with an alcohol dipped Q-tip, rinsing with a steady stream of water and pruning help to control these.
Controlling the White Flies in the Greenhouse
The white flies seem to be concentrated in the greenhouse, and have not become a big issue yet. There are over 1,500 species of white fly. These insects also suck the nourishment from the plants, but they are not easily picked off because of their small size and their wings which gives them the ability to move. Since white flies can transmit over 100 different plant viruses, they can become very dangerous in the greenhouse and must be controlled.
Best control is with yellow sticky traps or with a commercial insecticide. Because they spread so easily, we try not to bring in an infected plant. Any plant the madman acquires (he just got two at the Connecticut Cactus and Succulent Society’s meeting at UConn) will be thoroughly inspected before joining the greenhouse population. This control philosophy works well for us.
While taking care of watering and inspecting our plants over the past couple of weeks, the madman is often heard calling out “Who wants to go to the flower show?” He claims to be hearing tiny voices calling back, “I do, I do, I do…”
With that, it’s time for cocoa.
