I have copied and pasted Sandra's email for all of her recommendations for this weather (January 2024)
Here are the recommendations from 2 people I consider to be expert with regard to what to do when the weather gets cold:
#1.
I don't get too concerned if it's just one night for an hour or so, but when it's nights in a row and the days don't get hot enough to warm things backup, I start moving things into my protected back porch and when I run out of room into the house.
My rule of thumb is when under 55 degrees I start to be concerned about my vandas, cane dendrobiums and brassovolas. I don't grow grammatophyllums anymore but they don't like the cold either. Under 50 degrees I start to be concerned about the few phals I have, my maxillarias (coconut orchids), my encyclias and then start taking a look at my non-orchid plants.
I'm sure there are some exceptions, but generally your cattleyas and oncidiums will be fine.
Don't get confused about your dendrobiums and bring everything in, your nobile dens, pendant dens and den. aggregatum (lindleyi) need the cold to bloom.
If growing on trees, the trees help to keep them warm.
If you plan on covering things instead of bringing them in, do not use plastic. When the sun come out you can easily burn your plants.
You will know you have cold damage in about a week after the cold, leaves will turn yellow and start dropping. If you see leaves turning purplish or reddish that is a sign of a magnesium deficiency. If this happens, use potassium nitrate mixed with Epson Salts (1 tablespoon of each per gallon). The Epson Salts will provide the needed magnesium to green them back up. We have plenty of potassium nitrate in stock.
#2
Plants in good nutritional health will tolerate cold temperatures better and recover from injury faster than plants grown with suboptimal or imbalanced nutrition.
Methods of Protection
Plants can be moved into the house or to protective structures where there is more protection from the cold. If this is not an option, determine in advance which plants are most valuable to you. It is not a bad idea to mark those with a colored label or keep them all in a particular spot. That way, if you do need to gather them quickly, you will not be searching through perhaps hundreds of plants and labels to find them.
Also note which orchids in your collection hate cold. Many commonly grown orchids tolerate winter temperatures of about 55° F (13° C) at night, including some hardier Vandas, Stanhopeas, Oncidiums, some Dendrobiums, Cattleyas, Catasetums and cool-growing Paphiopedilums. Most Cymbidiums can take winter night temperatures in the 40's (4° C), and many need such a stimulus to bloom well.
White or yellow Vandas, as well as some Dendrobiums (Phalaenopsis-type, latouria, and antelope-type), are especially sensitive and do not like temperature drops below 60° F (16° C); they can be particularly prone to losing leaves when exposed to cold temperatures. Cattleyas tend to be more hardy and can tolerate lower temperatures better. The violaceas and dowiana cattleyas are more sensitive and need to be protected.
Grammataphyllums, Phalaenopsis, and Bulbophyllums are also very sensitive to cold and need to be protected. I know that many of you have very large Grammies. Try to cover them with a sheet or even newspaper to hold in the heat. If you have your led Christmas lights still available, you can wrap you large plants in them and cover with a sheet. It will keep them several degrees warmer!
Many of you have your orchids in trees and cannot move them. Trees are large heat sinks and so the roots and stems will stay warmer than those in pots, and the canopy protects the heat from escaping. So those plants will fair better.
It's important that the plants are fully dry before the cold hits. Moisture on the leaves will evaporate to the dew point which usually is much colder than the air, so you want your plants to be dry. We suggest not watering during this cold time. If you have automatic irrigation, turn it off until the cold is over.
Have wraps, clothespins, sheets, etc ready to cover smaller plants. Many materials can be used as insulating wraps. Frost cloth, available at most hardware stores, is lightweight and traps heat, but is designed to breathe as well. Sheets, blankets, towels, burlap and other coverings can also be used. We do not recommend using plastic.
If you have plants around a pool, you can run the filter all night. The turbulence from the water can generate heat transfer to the air for more warmth.
After the Fact
The effects of cold damage are not always immediate. A hard freeze, which we will not have, has immediate effects. But stress from long term cold weather, which we will have, may take weeks to see the full damage. After the last cold spell we had, the first thing I noticed, after a few days, was yellowing of the lower vanda leaves and discoloration on the Grammataphyhllums.
The positive side of the occasional winter chill is that, in many cases, cool periods help induce or enhance bud initiation and flowering. It also helps to promote dormancy in deciduous orchids.
Keep in mind that there are other cold sensitive plants that need to be protected like anthuriums, alocasias, medinillas and some other very tropical plants. If you have them in a pot, bring them into a protected place and, if not, cover them with a blanket, sheet, towel etc as suggested above.
Feel free to call me if you have any questions or concerns.
Sandra
Do It Yourself Household Cleaners
The healthiest, least-toxic cleaners you can find are the ones you make yourself. They're effective too: According to a study at Virginia Tech, spraying hydrogen peroxide and vinegar right after one another is just as effective at killing germs as lung-irritating, stream-polluting chlorine bleach.
EIGHT ESSENTIALS
These eight items make up the basic ingredients for nearly every do-it-yourself cleaning recipe.
Baking soda: provides grit for scrubbing and reacts with water, vinegar or lemon by fizzing, which speeds up cleaning times
Borax: disinfects, bleaches and deodorizes; very handy in laundry mixes
Distilled white vinegar: disinfects and breaks up dirt; choose white vinegar over apple cider or red vinegars, as these might stain surfaces
Hydrogen Peroxide: disinfects and bleaches
Lemons: cut grease; bottled lemon juice also works well, although you might need to use bit more to get the same results
Olive oil: picks up dirt and polishes wood; cheaper grades work well
Vegetable based (liquid castile) soap: non-petroleum all-purpose cleaners
Washing soda: stain remover, general cleaner, helps unblock pipes; should be handled with gloves due to its caustic nature. Washing soda is usually found in the laundry aisle of
grocery and drug stores.
Don't forget to pick up an empty spray bottle at the hardware store, and keep those old rags and used toothbrushes for wiping up and scrubbing.
All-Purpose Cleaner For The Whole House
1/2 cup borax
1 gallon hot water
Mix in pail (or use smaller amounts in a spray bottle: 1/8 cup borax to 1 quart of hot water) dissolving the borax completely; wipe clean with rag.
Floors
Wood
1/4 cup white vinegar
1 gallon warm water
Linoleum
1 cup white vinegar
2 gallons warm water
Mix in mop bucket, rinse afterwards.
Furniture Polish
1/2 cup white vinegar
1 teaspoon olive oil
Mix and apply with a clean rag to dust and polish. Reduce the olive oil if wood looks too oily.
Metal Polish
Copper and Brass
2 Tbsps salt
White vinegar
Add vinegar to salt until you've created a paste. Adding flour will reduce abrasiveness. Apply with a rag and rub clean.
Stainless Steel
Baking soda
White vinegar
Apply baking soda with a damp cloth, using the vinegar to eliminate spots.
BATHROOM
Toilet Bowl
Baking soda
White vinegar
To clean and deodorize, sprinkle toilet bowl with baking soda, add white vinegar and scrub with a toilet brush.
Tub and Tile
1/2 lemon
Borax
Dip the face of the lemon half in borax to create a hand-held scrubber for dirty areas. Rinse and dry the surface afterwards.
KITCHEN
Countertops
Marble: Mix one Tbsp castile soap with a quart of warm water, rinse well, then dry with a warm cloth.
Other surfaces: half a lemon and dip the face in baking soda to scrub off residues. Follow up by spraying with glass cleaner mix (below).
Drains
1 cup baking soda
1 cup vinegar
Add baking soda and vinegar to a pot of boiled water and pour down the drain, then flush with tap water. For more stubborn clogs, use a "snake" plumbing tool to manually remove blockage, or try suction removal with a plunger. To prevent clogs, install inexpensive mesh screen, available at home improvement and hardware stores.
Glass
1/4 cup vinegar or 1 Tbsp lemon juice
2+ cups water
Fill a clean spray bottle with water and either white vinegar or lemon juice; wipe with a rag or old newspaper.
Oven
Baking soda
Water
Sprinkle baking soda on surfaces, spray water, then let soak several hours or overnight. Rinse with water.
Stovetop and Oven Grease Remover
1/2 tsp washing soda (wear gloves)
1/4 tsp liquid soap
2 cups hot water
Add washing soda and soap to hot water in spray bottle. Since washing soda is caustic, wear gloves.
LAUNDRY ROOM
Bleach alternative:
1/2 cup hydrogen peroxide
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Why It Matters
In 2005, cleaning products were responsible for 9 percent of all exposures reported to U.S. Poison Control Centers. And, after bubbly cleaning liquids disappear down our drains, they are treated along with sewage and other wastewater at municipal treatment plants. However, wastewater treatment plants don't remove some of these chemicals completely, discharging them into nearby waterways where they threaten water quality, fish and other wildlife.
Chemicals of Concern
Conventional all-purpose cleaners are full of ingredients that pose both health and environmental hazards, without getting your home any cleaner. Steer clear of cleaners containing surfactants such as alkylphenol ethoxylates (APEs), DEA and TEA; nerve-damaging butyl cellosolve; chlorine; ammonia; fragrances containing phthalates; the antibacterial triclosan; and petroleum-based ingredients.
Misleading Claims
Not only are ingredients protected as trade secrets, the claims on cleaning products usually don't have any verifiable meaning. "Organic," for instance, refers to foods grown without synthetic pesticides in the grocery store, but in cleaners, it refers to chemicals that are carbon-based, including some volatile organic compounds (VOCs) that release harmful fumes and may cause brain damage or cancer. The USDA's National Organic Program doesn't yet regulate household cleaning products.