orchid yellow flower

Cold weather keeps gardening chores indoors. A recently acquired, but neglected moth or Phalaenopsis orchid came my way and needed some attention. I had another one on the window sill in need or repotting and set to the task. Moth orchids can outgrow their pots in about a year’s time as their wandering roots reach outside and above the edge of the containers. In their natural environment, they grow high in the trees, above the soil, taking all of their nutrients from the humid, tropical air, rain and debris which may land around the plant. This manner of growing is called epiphytic.  Leaves grow from a center grouping, sending roots out from just below leaf axis.

Mature plants usually flower late winter into spring. Flower show can last for several months. Repotting is best right after flowering. New orchids are often sold with roots packed in sphagnum moss to keep them moist during the shipping and retail portion of their life. Once home, moss and any plastic packing and pots should be carefully removed. Orchid roots like air and will rot if keep soggy and wet.

After removing moss.

Cut back any dead or rotted roots.

 

roots trimmed - Copy

After cutting back dead roots in moss.

pot half filled with roots above - Copy

Neglected roots cut back.

Phalaenopsis orchids prefer a porous pot such as terracotta which provides plenty of air. Some decorative orchid pots have holes designed in the sides for the roots to access more air. Water these plants and pots over the sink as water will readily run out.

Use specially formulated orchid bark mix for potting. The mix should contain bark, perlite and horticultural charcoal. Old bark deteriorates over about a two year period, and should be refreshed annually by repotting to keep the plants strong.

Fill the pots half full of bark mix, then set the trimmed root ball onto the bark, spreading out the roots carefully. Insert a plant stake or chopstick through the bark mix, next to the plant to help anchor the orchid.

pot half filled - Copy

Half filled with bark mix.

Gently add more bark mix over the roots to within one half inch of the top edge of the pot. Fill a large cooking pot or bowl with tepid water. Immerse the entire pot containing the bark and plant into the water to soak the bark for about 20 minutes. Then lift the terracotta pot containing the plant out of the water and let is drain in the sink. If settling occurs, add more bark. Orchids should never completely dry out. Keep the bark moist by soaking weekly, or water just the bark from above. Holes in pots are a must for good drainage.

Moth orchid should be placed in bright light, preferably east window. A south or west window will need a sheer curtain or the plant moved back out of the directly rays of sun to avoid leaf scorch.  In their wild home, they would be shaded by the tree canopy.

Orchids thrive in high humidity and temperatures around 75 degrees F with a slight drop at night. In the fall, reduced daylight and night temperatures of 55 degrees F will initiate flower bud formation. To provide more humidity, mist with clear water in the morning or set potted plant on a tray of pebbles and shallow water. The water will make a cone of evaporation surrounding the plant. Fertilize every two weeks with a balanced houseplant fertilizer during spring, summer and fall. Cut to half strength during the winter.

orchid 4

-Carol Quish

 

 

It’s that time of the year again: the Christmas holidays are days away. If you are looking for last-minute gifts for the gardener in your life then here are some ideas, including some new trends.

Herb-growing kits are one of the latest trends in indoor gardening. I always bring an herb planter in at the end of October when it gets too cold at night for it to remain out of doors. It generally does very well in a southwest-facing den window for a few months but the reduced sunlight and cooler nighttime temperatures usually cause it to gradually decline in vigor.

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Unfortunately, the window in my kitchen faces northeast and therefore is the least desirable growing spot in our house. There are many herb growing kits available now that have growing lights built into the units so that if you or your gift recipient also have a kitchen with a window that gets low light (or no window at all), fresh herbs can still be within reach of your culinary efforts.

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There are more than a few lower maintenance herb kits that come in a variety of containers, one of which is sure to fit the décor of any home. Burlap or heavy paper bags come complete with all that is needed to grow flowers and herbs.

The Eggling kits would be a great gift for a young gardener who would really enjoy cracking open the top of the egg to see that it contains everything (except water) that is required to grow herbs, strawberries, or flowers. Colored glass canning jars contain everything from herbs to palm trees!

Another way to grow fresh herbs or micro-greens is a portable water garden that incorporates a fish tank and a plant bed in a unique symbiotic relationship. We gave one of these to our daughter for her birthday in April and have seen the mini-aquaponic system in action. The cut-and-come-again micro-greens that sprout and grow to harvesting size in a week to ten days include radishes, broccoli, arugula, spinach, and wheat grass.

This closed system circulates the water from the fish tank up through the rock garden that sits atop the tank. As this water is rich in fish waste it supplies fertilizer to the plant’s roots. The water that is returned to the fish tank has been cleaned by the plants.

Once the herbs have been grown, whether indoor or out, there are special containers to keep them fresh and assorted culinary tools to prepare them such as a stripper that eases the removal of small leaves from herbs such as rosemary and thyme. A larger variation of the stripper works well with larger-leafed vegetables like kale. A cactus-shaped herb infuser allows any cook to add a bouquet garni to their cooking pot and then easily remove it before serving.

If your gift designee would prefer to adorn their table with flowers rather than grow them then there are plates for every style, from bold orange, green and black tropicals to powder blue backgrounds with delicate cherry blossoms to, my favorite, the high-contrast black and cream Queen Anne’s lace.

And of course, there is the traditional and always welcomed hostess gift of a flowering plant. Poinsettias are not the only way to brighten a home during the winter. Florist’s departments are teeming with an abundance of colorful blooms. Kalanchoe is a succulent houseplant that may be found with white, red, yellow, orange, and fuchsia long-lasting flowers.

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Anthurium, with its dark green, heart-shaped leaves and a tall spike of minute flowers that sit above a brightly-colored bract that may be white, pink, or red is a lovely houseplant.

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Flowering plants in the Cyclamen species include Cyclamen persicum and C. coum, both of which bloom in the winter and C. repandum which blooms in the spring would be welcome gifts. Cyclamen have beautifully variegated leaves and up-swept flower petals that range from white to soft pink to deep red.

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But if you are looking for a flowering plant that comes in a color to match any décor than nothing can top the appeal of the dramatic Phalaenopsis orchid hybrids. As seen in the image below, they are available in a veritable rainbow of colors.

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Here’s a  suggestion that may also be a final destination for plant and herb refuse: a kitchen compost bin. Now available in many materials and sizes, these bins make composting easy and may only need to be emptied on a weekly basis, perhaps a bit more often if the household is basically vegetarian like ours is or if there is a coffee-lover filling it with used grounds.

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If your gardener is also a coffee lover, then these mugs that reflect the current succulent houseplant trend would receive a warm welcome.

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Its not too late to shop for your favorite gardener or, if one or two of these gifts happened to catch your eye, then print this off, circle your choices and leave it where Santa may find it!

Susan Pelton

All images by S. Pelton

geranium_lemon, missouri.edu

Lemon Scented Geranium, photo from Missouri.edu

As cold weather arrives, my garden focus switches to houseplants. I am particularly fond of growing scented geraniums inside the home. They are easy to grow and smell great, releasing aromatic oils into the air when their leaves are gently stroked, refreshing the stale scents of enclosed houses. Houseplants in general are a great way to increase the moisture level of dry, winter-heated air as water is added to their soil, and some moisture will evaporate into the air surrounding the plants.

Scented geraniums are in the genus Pelargonium, the same as the annual geranium with the large red, white or pink ball of a flower head. Even though both of these types of Pelargonium are have the common name of geranium, neither are related to the true perennial geranium (Geranium maculatum), commonly called cranesbill. Pelargonium species are not hardy in areas with cold winters. Scented geraniums can be planted outside and treated as an annual in addition to being a houseplant. They are native to South Africa, and were introduced to Europe in the 17th century by plant collectors as was popular at that time. Scented plants were especially prized in that era of limited sanitation and personal hygiene. Leaves and flowers were used in tussy-mussies to be carried by ladies whom wanted to smell better. The plant flower a smaller pale colored flower, usually pink or lilac depending on the specific variety.

scente geranium, arnold arboretum, historical print

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mosquito_citronella_geranium_pelargonium_Barbara H. Smith, ©2018 HGIC, Clemson Extension.jpg

photo by Barbara H. Smith, ©2018 HGIC, Clemson Extension

Today scented geraniums are prized house plants for a sunny window or greenhouse. Leaves are edible, can be tossed in a salad or used as a garnish without fear of toxicity. Leaves are used as tea, and can be added to baked goods. Lining the bottom of a greased cake with artistically arranged leaves, then gently pouring in the batter creates a pretty and tasty dessert. Add one cup of fresh crushed leaves to simmering apple juice to make into flavored apple jelly following apple jelly recipe on pectin container. Dried leaves can be added to pot pourri and added to muslin sachet bags to place in a drawer. Sachets can also be used in hot baths or a relaxing spa experience.

The flavors or scents of scented geraniums are broken into several groups. The Rose Scented Group contain a number of different varieties with strong, clear rose scents to ones with a softer rose fragrance. Atomic Snowflake has a lemon-rose scent. Another scent group is the Citrus Scented geraniums. Lemon Crispum has a strong lemony fragrance, while Lime smells like a key lime pie. Prince of Orange sports crinkly leaves to emit its orange scent. The Fruit and Spice Group contain plants that smell like ginger, nutmeg apple and even strawberry. These are especially good in baked goods. The Mint Group, true to its name, has different plants with varying grades of minty scents. Peppermint, a peppermint lemon and a pungent peppermint with rose notes are all different. The last group is the Pungent Group with musky, oak, and camphor fragrances. It is best to feel the leaves and smell the plants before deciding to take one home to be sure it is agreeable to your nose and palate.

scented geranium, white flower farm photo

Scented geranium varieties, photo WhiteFlowerFarm.com

Growing requirements for all scented geraniums are fairly easy. They need a sunny south or west window or fluorescent lights, and well drained, light potting mix. Water them when the soil is dry to the touch. If the soil is keep soggy, the roots will rot. Drain any water from the saucer below the pot to avoid over saturation. Temperatures for optimum growth are in the range of 55 to 70 degrees F. Fertilize with a basic houseplant fertilizer every three month. Too much fertilizer leads to weaker growth and less scent production. Prune back the plant if it begins to grow too large, saving the trimmings of course!

Lemon Scented geranium at FS, DPettinelli

Lemon Scented Geranium on display at the flower show. photo by D. Pettinelli.

Every growing season brings a variety of inquiries into the UConn Home & Garden Education office, either by snail mail, email, or in person. This year was no exception and I would like to share some that I found particularly interesting.

As we are entering the Christmas season I will start with an image of a Christmas cactus with raised bumps on its leaves. Although they were the same color as the leaf they had a translucent appearance when viewed with the light from behind. These blisters are edema (oedema)are the result of a disruption in the plant’s water balance that causes the leaf cells to enlarge and plug pores and stomatal openings. Moving the plant to a location with more light and watering only when the soil is dry can control edema.

Edema on Christmas cactus

Christmas cactus with edema symptoms

The cold of winter can cause problems that sometimes aren’t apparent until later in the year. Tree trunks that are exposed to southern light during the winter can suffer from sunscald and frost cracks. Sunshine and warm daytime temperatures can warm a tree enough so that the sap begins to run but the nighttime temps will cause the sap to freeze and expand, weakening the bark and resulting in vertical cracks. Dogwood with sunscald (on left) and willow with frost crack (on right) are among the susceptible species.

 

There were several incidences of huge populations of black cutworm larvae emerging in the spring including a group that appeared to be taking over a driveway! The Noctuidae moth can lay hundreds of eggs in low-growing plants, weeds, or plant residue.

The wet spring weather that helped to alleviate the drought of the past two years also had an effect on the proliferation of slime molds, those vomitus-looking masses that are entirely innocuous. The dog stinkhorn (Mutinus caninus) is another fungus that made several appearances this year.

Hosta plants exhibited several different symptoms on its foliage this year and the explanations were quite varied, from natural to man-made. The afore-mentioned wet spring and summer or overhead watering systems can cause Hosta to have the large, irregular, water-soaked looking spots with dark borders that may be a sign of anthracnose (the below left and center images). In the image below on the right the insect damage that shows up as holes that have been chewed in foliage may be caused by one of Hosta’s main pests, slugs.

But one of the more enigmatic Hosta problems presented itself as areas of white that appeared randomly on the foliage. Several questions and answers later it was determined that the Hosta in question was very close to a deck that had been power washed with a bleach solution! Yeah, that will definitely give you white spots.

Bleach damage 3

That bleach bath also affected a nearby coleus (below on left). Coleus downy mildew (Peronospora sp.) also likes the cool the cool temperatures and humidity of spring (below on right). The gray-purple angular blotches of this fungal disease were first observed in New York in 2005. Fungicides can be helpful if used early and thoroughly, and overcrowding and overhead watering should be minimized.

The grounds of the residence where my in-laws live have a lot of flowering plants in the landscape and as we walked one evening I noticed that the white roses had spots of red on them. These small, red rings are indicative of Gray mold (Botrytis cinerea), a necrotrophic fungal disease that is also a common problem in grapes called botrytis bunch rot. The disease is a parasitic organism that lives off of the dead plant tissues of its host.

The fungus Gymnosporangium clavipes, cedar-quince rust, on Serviceberry warranted several calls to the center due to its odd appearance. The serviceberry fruit gets heavily covered with the aecia tubes of the rust which will release the aeciospores that infect nearby members of the Juniper family, the alternate host that is needed to complete the cycle of the infection.

Two other samples that came in, goldenrod (below on left) and sunflower (below on right), shared unusual growths of foliage. Sometimes plant aberrations can be the result of a virus (such as rose rosette disease), fungus (such as corn smut fungus), or, like these samples, phytoplasma. Phytoplasma is the result of bacterial parasites in the plant’s phloem tissue and can result in leaf-like structures in place of flowers (phyllody) or the loss of pigment in flower petals that results in green flowers (virescence). Phytoplasma parasites are vectored by insects.

A frequent question revolves around ‘growths’ of a different kind, in particular the white projections that can cover a tomato hornworm. These are the pupal cocoons of the parasitic braconid wasp. The female wasp lays its eggs just under the skin of the hornworm and the newly hatched larvae will literally eat the hornworm to death. As the larvae mature they will chew their way to the outside where they will spin their cocoons along the back and pupate. As the hornworm is effectively a goner at this point they should be left undisturbed so that the next generation of wasps will emerge to continue to help us by naturally controlling this tomato pest.

Tomato hornworm 3

Tomato hornworm with braconid wasp pupal cocoons

 

Another wasp that was caught in the act was the cicada killer wasp (Sphecius speciosus), a large, solitary, digger wasp. Cicada killers, also called cicada hawks, are so called because they hunt cicadas to provision their nests. It is the female cicada killer that paralyzes the cicada and flies it back to her ground nest. The male cicada killer has no stinger and although its aggressive nature can seem threatening to humans, the male spends most of its time grappling with other males for breeding rights and investigating anything that moves near them.

Cicada killer wasp

A cicada killer wasp paralyzes a cicada

 

Speaking of noticing what’s going on around you, as my husband was walking past a False indigo (Baptisia australis) in July he heard a strange cracking sound and called it to my attention. The plant in question was outside of a gym on the Hofstra University campus where our son’s powerlifting meet had just ended. As many lifters exited the building amid much music and commotion we stood their staring at the Baptisia, heads tilted in that pose that is more often found on a puzzled dog. The bush was indeed popping and cracking as the dried seed pods split open!

 

But none of our inquiries approach the level of oddity reported by a retiree in Karlsruh, Germany, who thought that he had found an unexploded bomb in his garden in September. Police officers called to the scene discovered not a bomb but in fact an extra-large zucchini (11 lbs.!) that had been thrown over the garden hedge.

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This is not an unexploded ordnance!

 

I look forward to next year’s growing season with great anticipation!

Susan Pelton

Through the Macro Lens

As the first month of 2016 nears its end it would appear that we are finally getting some true winter weather in the form of arctic cold and snow that will keep even the most ardent green thumb inside. Is it any wonder that January is a popular time for perusing seed catalogs and forcing paperwhite and amaryllis bulbs to bloom indoor? It also presents a great time to pay a bit more attention to our houseplants: cleaning the foliage, repotting specimens that have outgrown their current containers, and doing a visual inspection for insects. This year, however, checking for unwanted visitors took on a whole new meaning.

Poinsettia Flowers

I received a great present from my husband this Christmas in the form of a macro lens that clips over the camera lens of a smartphone (he knows how much I enjoy getting close-up images of insects and flowers). This tiny tool increases the magnification power of the ordinary camera lens by 10X allowing for some really incredible images from a phone camera. The first thing that I did with it was to start snapping pictures of just anything that was around such as the true flowers of a poinsettia that are usually insignificant, the new blooms of a paperwhite, and some fuzzy, cotton-like areas on a dieffenbachia.

What I saw in the lens was amazing. It was not just a cobweb substance on the dieffenbachia but a group of tiny insects that turned out to be the nymphs of the mealybug.

Mealybug nymphs 3

These tiny insects, along with scale and aphids, are a common pest of houseplants. They feed on the sap of the plant by piercing the outer layer of plant tissue with their long, slender beak. As a by-product they secrete a sweet honeydew that provides a base for the black fungus called sooty mold. Plant tissue that has been fed upon will be stunted, yellowed or malformed. A severe infestation can weaken a plant to the point of death.  I found that many of the mealybugs were in the crevices of the leaf axils or in the unfurled new leaf growth.

Mealybug nymphs 1

A bit of research showed me that one of the easiest remedies was to wipe the affected areas with an isopropyl alcohol soaked cotton ball. I did this, making sure to get both sides of the leaves as there were many nymphs on the undersides.

 

There are also many products such as insecticidal soaps and neem that can be used to control nymphs, scale, spider mites and aphids. These should be used with caution and always according to the label directions. A few more non-chemical approaches include spraying the plant with a forceful stream of lukewarm water, placing it near a cold window (only if the plant can tolerate the cold) so that the nymphs migrate to the leaf that is furthest from the cold and will therefore be easy to wipe off, or introducing a natural predator such as a ladybeetle (probably a good idea for greenhouse specimens, not plants in a home environment).

It is important to check for new generations of any insect pest that may not have been controlled with the first application. I have been scouting my houseplants every few days but I have not seen a recurrence. I can see, however, the results of the initial infestation. There are areas of foliage that are devoid of green, have turned brown and thin and almost appear like water spots. These areas are not much bigger than a quarter so I may leave that foliage on the plant and wait to see how it does.

I am really looking forward to getting outside in the upcoming seasons and getting some incredible close-up shots of flowers and insects, many of which will be shared with you in my blog posts. Happy New Year!

Susan Pelton

All images by Susan Pelton

Typically if it is January in Connecticut, one’s horticultural proclivities are turned towards indoor plants. I’m thinking this might be the beginning of another atypical year as temperatures in Storrs, CT were in the 50’s today and I had to water some outdoor hardy chrysanthemums under an overhang because they were wilting. These lovely burgundy mums have survived in this spot for almost a decade and they flower profusely each fall so I did not want to lose them. Usually the ground is frozen in mid-January and I throw some snow on them as a winter blanket. Snowfall has been in rather short supply this winter and the little I had covering them from last Saturday’s snowfall had melted quickly as temperatures rose.

In the case of these chrysanthemums, the young basal sprouts were wilting obviously because of a lack of water. I could see and feel the dry soil. Plants need water, just as we do, to grow and survive. Water is necessary for photosynthesis. It moves nutrients and photosynthates throughout the plant, it acts as a coolant and it gives a plant turgor along with many other less obvious but just as important plant functions. One might suppose that limited quantities of either natural precipitation or human supplied water would be the primary reason a plant would wilt. While it is a major one, there are three other situations where wilting could commonly occur – at least when dealing with houseplants.

Overwatering will cause a houseplant to wilt. In fact, I recall seeing somewhere that overwatering was the number one cause of houseplant death. Many houseplant owners like schedules (as a good number of us do) and water accordingly. So, if today is Saturday, it is time to water the houseplants. The problem is, the houseplants may or may not need water. When to water depends on the type and size of plant, the size of the pot, indoor temperatures, exposure to light, and the plant’s growth cycle among other factors. If heat is provided all or in part by a wood or pellet stove and plants are in this area, they will dry out faster and may need more than once a week watering. Those plants kept in a cooler, dimly lit area might only need water every 10 or 14 days. Our watering houseplant fact sheet (at www.soiltest.uconn.edu) may be of interest to new houseplant owners.

If plants receive too much water, the potting mix they are growing in becomes saturated. As this happens, any air in the root zone is pushed out and replaced by water. While this sounds counterintuitive to non-plant people, a plant’s roots need oxygen in the root zone to take up water. Once all the oxygen in the potting mix is replaced by water, the plant cannot take up water so they wilt. Usually the response to seeing a plant wilt is to add more water, thus exacerbating the problem.

What’s wrong with this plant?

Few roots, brown, unhealthy and overwatered.

Another scenario for wilting is caused by overfertilizing, especially with synthetic fertilizers, either in water-soluble or granular formulations. Fertilizers are primarily composed of nutrient salts. We use sodium chloride as our table salt at mealtimes, while some examples of fertilizer salts that are used to supply nutrients to plants include potassium chloride, ammonium nitrate and superphosphate.

You may have heard it mentioned that nature is always striving to reach an equilibrium (no matter how short lived it may be!). Well, if there are more nutrients in the potting mix, because of over-fertilization, than in the plant, curiously, the plant will release some of its water to try to dilute these salts so that the concentrations within the plant and surrounding the plant’s roots are more in line with one another, i.e. in equilibrium. In doing so, the plant loses water and wilts. On top of that the fertilizer salts can cause physical injury by the ‘burning’ or desiccation of plant root tissue. As plant roots die, there are less healthy ones to take up water so plants may still look water-deprived. Also injured roots because of overwatering or overfertilizing become susceptible to a variety of rot diseases.

Lastly, that plant that needs water on a daily basis probably is trying to tell you it needs to be repotted. There are so many roots growing in a restricted area that more water than you can supply it is needed. If plants are repotted on a regular basis, they are typically moved into pots that are one to two inches in diameter larger than the one they are presently growing in. If the roots are terribly overcrowded, you might select a pot that is 4 to 6 inches wider if the roots are not cut back. Do untangle or slice through encircling roots before repotting.

Spider plants need to be divided regularly to avoid overcrowding.

It is up to you, the houseplant caregiver, to figure out why your plant is wilting. Start by knocking the plant out of the pot and looking at the roots. They should be nice and white and crisp and the potting mix should be moderately moist but not dripping water or desert dry. If this is not so, try to figure out what has gone wrong. If you are stuck, please give us a call. Find our contact info at www.ladybug.uconn.edu

Happy Gardening,

Dawn