Cycads are palmlike plants that belong to a group called gymnosperms, which means cone-bearers. Often called "living fossils," they co-existed with dinosaurs and are essentially unchanged after millions of years. They grow as separate male and female plants that tolerate poor conditions well. Cycads vary in cold-hardiness, but all need only basic care and a bit of extra attention now and then to thrive outdoors or as container-grown indoor plants.
Well-Drained Soil and Fertilizer Are Essential
Cycads need soil that doesn't hold water for long periods and prefer a sandy or gritty type that drains quickly. If your plant is growing in the garden and you notice that water tends to stand at its base after a rain, dig gently around its base to a depth of about 4 inches and mix in some coarse sand to improve the soil's drainage. If your cycad is container-grown, ensure the pot has one or two drainage holes and allow it to drain fully after watering, never letting the plant sit in a water-filled saucer. Whether grown outdoors or indoors, feed a cycad yearly in spring with an organic, 3-1-3 fertilizer that also contains trace nutrients, diluting it at a rate of 1/4 teaspoon per gallon of water, but check your label for additional instructions.
Sun or Shade Can Work
Cycads are tolerant of different light conditions, depending on the variety. For example, the virgin palm (Dioon edule) prefers partial shade, while the cardboard palm (Zamia furfuracea) grows well in full sun, although it also tolerates some shade. These cycads grow in U.S. Department of Agriculture plant hardiness zones 8 through 11 and 9 through 11, respectively. Indoors, most cycads do well in bright natural light, such as a spot several feet away from a west- or south-facing window, but shouldn't be kept in direct sun that shines through glass for any length of time, because this can scorch the leaves.
Even Moisture Is Important
Although cycads are drought-tolerant plants, they do best when their soil is kept evenly moist, especially during spring and summer when they're actively growing. If your cycad is grown in a pot indoors, don't let its soil dry out; keep it slightly moist at all times. Outdoors, give a cycad extra water whenever your area experiences a dry spell, aiming for about 1 inch of water weekly. Adding 3 or 4 inches of organic mulch to the ground at the plant's base also helps conserve soil moisture, while keeping down weeds that compete for soil moisture and nutrients, but keep mulch back from a cycad's trunk to prevent fungal problems.
Prevent Pests and Diseases
Although cycads are usually free of pests and diseases, they can attract hard-bodied scale insects that looks like raised dots on stems or leaves and suck plant juices, causing wilting and poor growth. These can be controlled by spraying with a water-soluble horticultural oil called white oil, diluted at a rate of 2 ounces per gallon of water and applied whenever scale appears. A cycad might also develop stem or root rot, fungal disorders that appear when conditions are overly wet. Rot is best prevented by planting only in outdoor locations with good air circulation and keeping an indoor plant where air moves freely and conditions aren't damp. Avoid overhead watering to keep foliage dry, and don't allow water to collect at the center of the cycad's rosette of leaves, where it might cause long-term wetness that leads to rot.