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Posts Tagged ‘Houseplants’

I wasn’t surprised the other day when I walked into my local grocery store and saw a table full of cyclamen, poinsettia, and Christmas cactus. But wait-what in the name of Asa Gray was that!? It looks harmless, doesn’t it?

 

The sign said it was a “Frosty Fern,” but I knew it wasn’t a fern, so what was it? It looked familiar but… And why had it been dipped in whatever it had been dipped in? I ran my hand over it-it felt like a cedar leaf. Then it finally hit me-clubmoss, of course-I had just done a blog entry on clubmoss! But that still left the nagging question of the “frosting.” Was it natural?

As it turns out, according to several websites, the coloring of the leaf tips is natural; similar to variegation on other leaves but concentrated in one area, apparently. This club moss (Selaginella kraussiana ) seems so unfamiliar because, though it has become naturalized in parts of Portugal, Spain and New Zealand,  it is originally from Africa.

Here in the northern United States it is grown as a houseplant and, by the sounds of it, a rather fussy one. Though several websites say it is easy to grow, they go on to say that it likes temperatures in the eighties, constantly moist soil, and very high humidity. It doesn’t like temperatures below fifty degrees and anything below ten degrees will kill it. “Easy to grow” is a relative term; I’ve grown so many houseplants in the past that it used to be wise to bring a machete if you came to visit, but I’ve always stayed away from those that need high humidity because it is almost impossible to provide it adequately. Many growers recommend putting the frosty fern in a terrarium which, in our dry winter houses, is probably a good idea.

In southern and western states frosty fern and its commercially available siblings “Aurea,” which is plain green, “Brownii”, which appears to be a dwarf variety and “Gold Tips,” which is frosted with gold instead of white are being planted outdoors in gardens and are escaping. They have become naturalized in Georgia, northern Virginia and central California and have escaped gardens in Alabama and North and South Carolina. They are being found on riverbanks, lake edges, lawns, and other moist, shady places, but the U.S.D.A. doesn’t list them as invasive. Yet.

In New Zealand Selaginella kraussiana, introduced as a groundcover, has been listed on the National Plant Pest Accord and is considered an invasive species. It spreads quickly by rhizomes (underground stems), forms dense mats in shaded areas and chokes out native orchids and ferns. Biological control has been unsuccessful and it takes several applications of herbicides to kill it, so repeated deep hand weeding is recommended.

It has also escaped and become naturalized in parts of Australia, Europe, and Northern, Central, and South America. Invasive plants “adversely affect the habitats they invade economically, environmentally, and/or ecologically.”  Many would never become invasive without a lot of help from us-the gardening public.

 

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Spiders on your plants aren’t a bad thing. In fact, spiders eat many of the insects that damage house plants, so they really should be left alone. Seeing a spider in the house might be just a bit too much to bear for some, but a house with spiders is more likely to be insect free. (Spiders are not insects.) Though there are dangerous spiders known in the U.S., here in the northeast most spiders living in our homes will be the common house spider, which is relatively harmless.

Spider mites, on the other hand, are critters you definitely don’t want on your plants. Spider mites build webs like spiders and are in the same arachnid family. Some mites cannibalize their own kind, but most prefer plant juices and will pierce a leaf or stem and then suck the plant juices and nutrients from it. This weakens the plant, and large infestations might even kill it.

Plants with spider mites will show small yellowish-brown spots on their leaves. These spots might be quite far apart at first, but as the colony grows leaves will have so many spots that they will appear off color and have a metallic bronze appearance. Small webs on the undersides of leaves and where the leaf meets the stem are where eggs will hatch. To check a plant for these tiny creatures, hold a piece of white paper under a leaf or branch and give the plant stem a couple of good taps. Spider mites will fall off if they are present and appear as small, rust red, moving dots on the paper. (You might need a magnifier.) Mites can travel from plant to plant on a slight breeze, so infected plants should be quarantined or thrown away if inexpensive.

Spider mites like it hot and dry, so keep humidity high by frequent misting and grouping plants together. Keep plants shaded from hot afternoon sun or consider keeping your plants in a sunny room in which the heat has been turned down. Most houseplants will do better at 65° F (18° C) than they will at 75° F (24° C) and you’ll save fuel.

Once spider mites appear on a plant control can be difficult unless spraying is done regularly. Eggs hatch in 4-5 days and mites will reach egg laying adulthood in a week or less. A strong isopropyl (rubbing) alcohol and water solution of 2 parts alcohol to 3 parts water should be sprayed twice weekly for at least 3 weeks.  It is very important to spray the undersides of leaves thoroughly along with the rest of the plant. Houseplants should be inspected regularly, even after spraying, so infestations don’t get out of hand.

Before spraying any plant with alcohol always test a leaf first to see if the plant will be harmed by it. Furry leaved plants should not be sprayed. Always protect surfaces and fabrics from alcohol sprays.

Photo magnification of Two Spotted Spider Mite by USDA-ARS-SEL & EMU, using Low Temperature -SEM

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The big difference between paperwhite narcissus (Narcissus tazzeta or papyraceus) and any other daffodil is that paperwhites don’t need a cool period, which means that they can be easily grown indoors as soon as you buy them with no extra work.

These bulbs are native to the Mediterranean region and are hardy only in zones 8 through 11. Here in the northeast if we plant them outside we have to treat them as we would any other summer flowering bulb, like dahlias or gladiolus. Paperwhites are available as soon as tulips and other spring flowering bulbs appear. When buying them, buy enough for a lengthy succession of bloom so you’ll have flowers throughout the winter.

To grow paperwhites all you really need is water, sunlight, and something to keep them from tipping over. (They can get quite tall if they don’t get enough sun.) I use shallow glass bowls about 4 inches deep and big enough to hold 3 to 5 bulbs. You should use a bowl with no drainage holes that is deep enough to contain the roots. I usually use plain pebbles or marble chips to give the bulbs support, but colored glass beads, washed gravel, or even colored aquarium gravel will work.  Put about an inch of gravel in the bottom of the bowl and nestle the bulbs down into it so the bulb sides are touching. Then fill around the bulbs with more stones or gravel until only about 1/2 to 1/3 of the bulb tops are exposed. Finally, fill the bowl with enough water to cover just the base of the bulbs. Set them on a cool, sunny windowsill and in about a month your house will be filled with their sweet fragrance.

  • Once bulbs are watered they should never be allowed to dry out or they may not bloom.  Check water level every other day with a finger if not using a see through container.
  • Pot up new bulbs every 2 weeks for winter long blooming.
  • As soon as bulbs set buds move them out of direct sunlight and they will blossom longer.
  • If the plants get too tall and begin to flop over, for your second bowl of bulbs follow the above directions but after a day of allowing the bulbs to absorb water, pour out any remaining water in the bowl. Immediately replace the water with a mixture of 9 parts water to 1 part alcohol. This can be vodka, gin, tequila, whiskey, or rubbing alcohol. Water the bulbs with this mixture from then on.  Researchers at Cornell University have discovered that alcohol affects the height of paperwhites but still allows them to bloom as usual. Do not use beer or wine as they contain sugar.
  • Paperwhites can also be planted in potting soil. Plant so 1/2 to 1/3 of the bulb is exposed above the soil line and keep constantly moist.
  • People bothered by strong fragrances may be sensitive to paperwhites. They are very fragrant and just 3 bulbs will fill an entire house with fragrance. You might try growing just one to start with if you have questions.

Photo copyright University of Florida Extension Service

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