You might be surprised to learn that cacti are among the best-known warm-weather plants and can suffer freezing damage. However, even in Arizona’s hot and dry summers, wintertime lows of 32 degrees Fahrenheit (0 degrees Celsius) are not uncommon. Cactus may suffer freezing damage as a result of this. You’ll need to know how to care for a frozen cactus if you discover that your cactus is harmed after a cold spell. Can you revive a frozen cactus? How can a frozen cactus be revived? For advice on helping a cactus harmed by cold, continue reading.
How cold must it be for cacti?
If you have enough light, cacti are some of the most rewarding houseplants. Few blooms can match them in terms of color, size, or beauty. Space is typically not an issue because most cacti grow slowly. They are extremely resilient and flexible. They do not “thrive on neglect,” unlike what the general public thinks. They “thrive on gentle loving care, like most plants, but they will at least “survive on neglect.”
Except for epiphytic (tree-dwelling) cacti and succulents like the Christmas cactus, rhipsalis, and orchid cacti, which demand less sunlight, greater humidity, and more watering than other species, the general care instructions below apply for cacti and most other succulent plants. They also prefer fertilizer with a higher nitrogen content. Compared to other species, add less sand to your potting mixture. Other succulents such as haworthias likewise favor brilliant indirect light over direct sunlight.
Give cacti and other succulent plants the brightest or most sunny windows you have indoors (four to six hours of direct sun). They will grow abnormally long and thin in low light conditions. Your plants will benefit greatly from spending the summer outdoors in the morning or late afternoon sun, when there is greater air movement and light. The majority of succulents can withstand intense outdoor sun, but they must get used to it. When putting plants outside, place them in partial shade or shadow at first and gradually expose them over the course of a few weeks to the strong late spring and summer sun.
Spiny and woolly species need the greatest sunlight, whilst spineless species typically need shade during the midday hours. If your plant has a reddish tint, it may be because the amount of sun it can withstand is reached or exceeded.
When you water, make sure to water well and wait until the soil has dried before doing so again. In particular, succulents are vulnerable to rot from excessive watering. If the earth around your plant is already moist, NEVER water it. Pots that are dry weigh less than wet ones. When the soil inside clay pots is moist, they feel chilly and damp to the touch. When the soil has enough moisture for the plant, succulent leaves are solid and plump.
The majority of cacti and several other succulents prefer to maintain a significant amount of dryness during the cooler months of the year (usually October through April). Over this time, drink less water than usual. To encourage new growth in the spring, spray your plants in the early morning hours of warm days. The spines of plants will allow them to absorb moisture. In order to prevent new roots from being stifled by excessively damp soil during the early spring, we also advise watering plants from the bottom of the pot. Fill the plant’s saucer with water, give the soil, pot, and plant around 30 minutes to absorb the moisture, and then drain the extra.
If you embed your plants in a mixture of 50% coarse builder’s sand and 50% peat, they will grow to their fullest capacity if they are in clay pots. This stops the soil from drying out too quickly and enables the roots to grow in the consistent wetness that the peat/sand mixture creates. Make sure there is excellent drainage in the tray that contains the peat/sand mixture.
Keep succulents and cacti above freezing in the winter. Some plants require a temperature range of 35 to 40 °F at night (some cacti and other succulents can endure temperatures well below freezing if kept absolutely dry.) A minimum temperature of 50–60 degrees is preferred for more tropical succulents like adeniums, euphorbias, lithops, and stapeliads.
Plants need to be shielded from intense heat in the summer since potted plants’ root systems are more susceptible to harm. Good air circulation and cautious watering will prevent fungal and rot issues in humid and hot conditions.
From May to September, feed your plants once per month using a fertilizer that contains low nitrogen (10% or less), such as 5-10-5 or 10-30-20. Nitrogen overload promotes excessively quick green but weak development. As the majority of cacti have evolved to thrive in nutrient-deficient soils, always dilute the fertilizer more than the label recommendations suggest.
In the spring or early summer, repotte. When young, most plants like annual repotting with just one pot size increase. Without relocating the plant to a larger pot, you can carefully remove the top inch or two of soil after you reach roughly a 6-pot size and replace it with fresh mix. Since succulents are typically heavy plants, especially when potted in clay, moving them into ever bigger containers can be challenging.
Steer clear of soils that contain a lot of peat moss. Peat retains moisture for too long and is difficult to remoisten after being fully dried (a frequent occurrence with most succulents). You can add some coarse builder’s sand to the soil to promote drainage and a tiny amount of peat to the soil to improve texture. As much as 40% sand is appreciated by stapeliads, wooly cactus, and lithops (living stones). The base of the plant should have a top dressing of fine gravel since it encourages greater water absorption into the soil, shields it from excess moisture, and looks good too. For every 3 inches of pot size, add a tablespoon of gypsum and bone meal, if possible.
Use a pair of wooden tongs or a piece of newspaper that has been rolled up to help plants with a lot of spin out of their pots. If the plant is resistant, resist the urge to pull it out because doing so will harm the roots. Try again by striking a hard surface with the pot. As much soil as you can take out without harming the root ball. To prevent rot, always repot the plant at or higher than the prior soil level. You might need to stake species of columns. To give new root hairs time to grow after repotting, wait a week or two before watering.
When it freezes, do you need to cover the cactus?
Bring the cactus inside if you’re growing it in a container. Use burlap, bed sheets, or frost blankets to cover landscaping plants in the late afternoon. Set up the coverings with a supporting framework if necessary so they don’t contact the plant. The following morning, when it is above freezing once more, take off the blankets.
Put a 60-watt light bulb under the blanket and leave it on all night if a severe cold is predicted. Cover just the more delicate younger growth at the stem ends of columnar cacti in light frost with polystyrene cups.
How can I keep my cactus from freezing?
Cover your cactus’ developing tips with styrofoam cups. This will keep them from freezing. They won’t be harmed by it. The majority of cacti are currently inactive and not growing. This past summer’s growth was delicate and has to be protected.
To prevent it from being blown off by the wind and endangering your plants, tie on any frost protection you use. Large-bulb Christmas lights will also keep plants warm, especially those big specimens that could be challenging to cover.
Never use plastic on your plants directly! Plants will freeze as a result of this moisture trap.
What happens if my cactus freezes?
The flesh of a frost-damaged cactus may initially appear white. After that, frost-damaged cacti will soften, wilt, and become black. Some cactus can naturally shed these frozen regions. However, if you believe the dead plant sections are becoming contaminated, you might choose to trim them off.
When should I bring indoor cacti?
In their natural environments, which are primarily in North and South America, cacti experience torrid summers with little to no precipitation. As a result, they cease growing in the summer (dormancy) and resume it in the middle of the fall, when the rainy seasons begin.
The majority of cactus owners keep their plants indoors, so they have hot, humid summers but chilly winters. In this situation, winter is the time to start your cactus’ dormancy (mid October-end February).
It’s crucial to let your cactus hibernate throughout the winter if you keep them indoors. Cacti can “relax,” produce flower buds, and get ready for summer growth during dormancy.
Do all cacti need a dormancy period?
No, not all cacti require a time of hibernation. Cacti in the desert will benefit from a dormant time indoors. Tropical cacti, including those of the Rhipsalis, Schlumbergera, or Epiphyllum genera, do not require a period of dormancy.
Please make sure that temperatures are a little warmer for tropical cactus during the dormant season. Wintertime temperatures for tropical cactus should be between 54 and 59 F. (12-15 C).
Higher humidity is something that tropical cactus enjoy and actually experience in their natural habitat. So you may sprinkle the plants from the top while they are dormant.
Step 1: Reducing watering frequency
Reduce how frequently you water your cacti as the first stage in beginning your cactus dormant period. This is crucial since reducing watering will help prevent the roots of your cacti from drying out and dying.
Additionally, since water evaporation would be less at cooler temperatures, it will aid in preventing rot (next step). Be sure to cut it back gradually. If you were watering your cacti every two weeks throughout the summer, cut down to every three weeks in the early fall and then just once every four to six weeks during the winter.
Never completely cease watering dormant cacti; doing so will cause root loss and stunted development. Your cactus will survive the winter with a little light watering. A soil meter similar to this one can be used to measure the soil’s moisture content.
How long should my cactus be left outside?
The fact is that cacti plants can struggle throughout the winter. If you don’t shelter them from the bitter cold, they can perish. The cold will make them look dull. However, this does not obligate you to bring your plants inside each time the winter weather arrives.
Many gardeners are shocked to discover that there are numerous varieties of cacti plants that can endure all four seasons outside, even the winter. Sadly, in the world of cacti plants, the cold-hardy kinds are frequently disregarded. Many folks aren’t even aware that they exist.
Check the cacti plants’ level of cold resistance before purchasing them if you intend to keep them outside all year.
The iconic Opuntia family of prickly pear cacti include the true champions of frigid climates.
There is typically a vast variety of sizes, forms, and colors among the Opuntia species. They feature flowers that might be red, yellow, or bright pink and grow close to the ground.
Opuntia fragilis, which can endure temperatures as low as -35oF, and Opuntia poryapantha, which can withstand temperatures as low as -25oF, are two of the toughest cacti species in the Opuntia family.
The Opuntia compressa species thrives across the majority of the United States and Canada and is also cold-hardy. Additionally tasty are its luscious crimson fruits. Cylindropuntia, Corynopuntia, Escobaria vivipara, and Echinocereus are some of the other cold-tolerant cactus species.
Growing cold-tolerant cacti plants does not, however, imply that you should neglect to provide them proper care during the winter. You’ll still need to devise strategies for shielding them from severe weather.
Due to the fact that some species of cactus are native to freezing desert environments, they can withstand temperatures as low as 20 degrees below 0 degrees Fahrenheit. These plants may exude water, which will give them a slightly deflated appearance, or they may contain spines or hairs that deter frost. However, many cacti cannot withstand cold or temperatures below zero. Always examine the hardiness zone of a cactus before purchasing. Bring your cactus inside as a houseplant if you reside in a location outside of its range. Row covers, tents, and frost cloths can all be used to protect your cactus from the bitter cold outside.
To review, humidity is the quantity of water vapor in the atmosphere. Cacti typically like low humidity and good airflow, though they do appreciate water after drying up. Winters are frequently dry, so keeping your cactus next to a heater inside won’t cause any issues. The air outside is frequently dry due to wind chill. Keep an eye on the humidity if you live somewhere where it gets cold and humid. If the relative humidity exceeds those ranges, you might wish to bring your cactus indoors because most cacti like a relative humidity of 40 to 60 percent.
How are cacti prepared for winter?
Cacti and succulents are excellent low-maintenance plants that add color to the home even on the gloomiest winter days. They provide aesthetic appeal to any table or windowsill with their unique forms and textures, and with proper care, they’ll last the entire long, cold season.
Cacti and succulents are suitable indoor plants all year round. Plants simply only a little light and sporadic watering during the winter. By the time fall arrives, the majority of cacti and succulents have gone dormant and will no longer grow as the weather and light conditions change.
5 Techniques for Winter Cactus and Succulent Care:
1. Plant your dormant plant in a location where it will flourish to make your cacti or succulents happy. During the winter, succulents require less light and can also tolerate indirect light. Make sure your plant receives at least three to four hours of bright light each day for the best results. Locations are happiest close to windows that face south or east.
2. Sandy, well-drained soil is best for growing succulents. Give your plant the nutrients it requires by using Espoma’s cacti and succulent mix. Make sure containers have drainage holes to allow extra water to drain because succulents can’t tolerate excessively moist soil.
3. Set the thermostat. Few succulents can withstand temperatures that are much colder than 50 to 55 degrees.
4. Succulents require deep watering, although they won’t need as much as they do during active growth. Use little water and only from the top, letting water seep through to the bottom. Keep plants out of water for brief periods of time. Keep water away from the cactus’ body since it can cause decay.
5. Look for vermin. Check your leaves every month for mealy bugs and aphids. If a plant is infected, remove it from the vicinity of other plants and spritz it with a solution of 3 parts rubbing alcohol to 1 part water.