Aloes include hundreds of species of succulent plants with thick, spear-shaped leaves. They may have spines or teeth to protect their leaves and grow with or without a stem. There are only a limited number of species that stay small enough to be good houseplants.
As succulents, aloes have adapted fleshy leaves for water storage. The leaf is further protected by a thick skin and waxy layer which, on close examination, is covered with a distinctive pattern. The relatively large interior to exterior area ratios of these plants reduces loss of water into the atmosphere. They originate mostly in sub-Saharan Africa, the Arabian peninsula and Indian Ocean islands, in a variety of the less moist habitats.
Aloes are adapted to the dry, winter conditions suffered by most New York area houseplants but they are somewhat difficult to grow indoors because they need very generous amounts of daily sunlight. And many of the small, architecturally attractive aloes purchased for the home quickly outgrow the size and form that enticed the buyer. Here are some rules of thumb for successful indoor cultivation of aloe plants in our area.
Light is where many succulent gardeners fall short of the needs of their plants. It is critical that you place your aloe in a window where it will receive a minimum of six hours of sunlight per day. Without extended, direct light, your succulent will begin to stretch and lose its attractive, compact form. It may topple over as the stem grows weak. (More on lack of light and other reasons for Aloe Flop below.) Aloe variegata (partridge aloe), is a popular dwarf aloe that prefers strong sunlight, but indirectly.
If the sun in your sunniest window is not adequate, artificial lights should be considered, alone or in combination with natural light. A white fluorescent light, 6 to 12 inches above the plant will give good results. Artificial light is not equivalent to daylight in strength and must be delivered for at least 14 to 16 hours per day. (For more detailed information on choosing an artificial light for your succulent plant, click on the Needles + Leaves link.)
Too much water is the most frequent cause of succulent failure and watering your aloe requires care. Your watering regime should vary with the time of year. Typically, in the low-light conditions of winter (October through February), water only as often as is necessary to prevent the soil from drying completely. Your plant is not in active growth at this time and prefers extended dry conditions.
When you water, water thoroughly, allowing the water to run from the bottom of the pot and checking back after 15 minutes to remove any water sitting in the plant's tray. As daylight hours increase and the plant comes back into active growth, water more frequently but continue to let the soil nearly dry before adding more water. Succulents have shallow roots and they will rot easily if over-watered. They do not need humidity to prosper and misting is not advised. Do not allow water to stand in the leaf rosette of the plant.
Some aloes are sensitive to fluoride and may exhibit brown spotting as a result. Use rain water or purified water if possible.
Succulents are happy with the temperature conditions achievable in New York area households. Daytime temperatures of 60 to 75°F. and night time temperatures ranging from 50 to 60°F. are well tolerated. Succulents prefer at least a 10-degree temperature fluctuation from day to night in order to grow successfully.
Your home is full of microclimates. Locations near windows may be sunny during the winter, but they are also cool (usually 10 degrees colder than the center of the room). In the summer, a south-facing window gets hotter during the day relative to the rest of the room and the rest of the house. Investigate your home’s microclimates in order to place your plants in the best spots. You may need to move plants to the most comfortable location for the season. An aloe that has gotten chilled by sitting on a cold window sill or in a draft will discolor.
The soil and pot you choose for your aloe plays an important role in its health. Moisture trapped around the negligible root systems of these plants can lead to sudden death. Your pot must have a draining hole at its bottom. The ideal soil should resemble the loose, free-draining mixture of a succulent's native habitat. Equal parts potting soil, peat and sand are generally best. Commercial cactus mixes are acceptable, if not ideal, and readily available but avoid those that have food already in the mix. Sprinkle perlite or coarse sand on the surface of the soil to protect fleshy leaves from moisture and rot. Repot in July or August for older plants. Do not set the plant any more deeply into the potting soil than it has been growing in its old pot; burying the stem will lead to rot.
Succulent plants are frequently sold grouped together as a miniature garden in a shallow pot but these conditions may not benefit your plants. The shallow containers are chosen for charm not drainage and frequently lack the hole at the bottom necessary for survival. Different plants need varying amounts of moisture and grow at different rates; often one plant will dominate and eventually choke out the rest. Not the pretty picture you hoped for when you purchased your miniature garden!
If you have a grouping like this, keep an eye on it and separate out any plants that are not thriving or are dominating in the group. They may need a new location as well as their own pot. If your miniature garden lacks a drainage hole, consider re-potting in a container that will give these plants a better chance of survival. If transplanting, take care with the delicate roots.
Minimal nutritional intervention is required. Aloes should be fed only during their growing season (March through September). A balanced organic houseplant food, fed at half strength, once a month to three months, is advised. Any plant food with a high nitrogen value should be avoided.
It is very important to differentiate the non-active growth period of your succulents and to give them a rest. From October through February, most succulents need reduced water, food and temperature, though direct sunlight should continue.
is a common problem that can happen for several reasons. Some aloes simply have a growing habit that keeps them low to the ground or sprawling in form in their native habitat and looks like a collapse when it happens to your houseplant. If you are growing Aloe brevifolia (short-leaved aloe) or another aloe with a stem clothed in leaves, you may be seeing your plant's natural form when it grows a foot or so in height and then begins to tumble over the side of the pot.
Clump-forming aloes may stretch over the sides of a pot as the multiple plants outgrow the pot surface. Other aloes become lax in shape as they age and vary from what you may have expected based upon your plant's immature form. It is natural for the older, outer leaves of a mature Aloe vera to droop somewhat and sprawl away from the center of the plant. This is how your plant will continue to grow and you should not try to change its habit.
Aloe flop also occurs if your plant is not receiving adequate sun and the leaves or stem do not have the strength to grow in the pleasing upright form you expect. Leaves will appear limp, flattened and elongated.
A third, common reason for an aloe to sag, is over-watering or soggy soil, particularly in winter. In the low-light conditions of winter (October through February), water only as often as is necessary to prevent the soil from drying out completely. Check that you have the correct, fast-draining soil and that your container has an unblocked drainage hole or soggy soil and ensuing root rot can occur despite watering restraint. Over-watered leaves will look bleached and weak.
If your aloe is flopping over, ask yourself:
can hide in the plant rosette or bury themselves in the roots. Remove any that you see manually, after dabbing with alcohol on a cotton swab. Examine the plant regularly for additional insects.
Crazy about Cacti and Succulents by 
The Timber Press Guide to Succulent Plants of the World by 
