How to Grow and Care for Autograph Tree

The autograph tree, also known as balsam apple or pitch apple, is an evergreen tree with a short trunk and thick foliage. You can easily scratch your name into the leaves with a fingernail and the scarred lettering will remain, hence the tree's common name. Autograph trees grow best in tropical, full-sun conditions and in most soil types, though they can tolerate partial shade. The leaves, and especially the fruits, of the autograph tree are toxic to pets and humans.

Common Name	Autograph tree, balsam apple, pitch apple
Botanical Name	Clusia rosea
Family	Clusiaceae
Plant Type	Tree
Mature Size	25-30 ft. tall, 15-25 ft. wide
Sun Exposure	Full, partial
Soil Type	Loamy, sandy, clay, well-drained
Soil pH	Acidic, neutral, alkaline
Bloom Time	Summer
Flower Color	White, pink
Hardiness Zones	10-11 (USDA)
Native Area	Central America, Caribbean
Toxicity	Toxic to people, toxic to pets

Autograph Tree Care

Here are the main requirements for growing an autograph tree:

• Choose a bright, sunny spot outdoors, or if growing as a houseplant, choose the sunniest spot possible.
• Plant in well-drained soil, especially if planting in an indoor pot.
• Outdoors, water while the tree is becoming established in its first year or so, but otherwise, it should be drought-tolerant. Indoors, water thoroughly once the soil has become dry.
• You can fertilize occasionally with a standard tropical plant fertilizer as instructed on the package to encourage growth, though it may not be necessary.
  

Warning

The autograph tree is listed as one of Hawaii's most invasive horticultural plants.

Light

Full sun is best, but this plant can tolerate partial shade. When it is grown indoors as a houseplant, it will cope with medium light levels and some degree of shade.

Soil

A sandy, soft, loose, well-draining soil is best, though the autograph tree can grow in a wide variety of soil types outdoors. Soil should be fertile and rich in organic matter. When growing in pots, blend the potting mix with a small amount of growing medium for orchids.

Water

The autograph tree should be watered regularly for the first year until the plant is fully established. You can scale back its water after that, although regular watering will help it grow more fully. This species is fairly drought-tolerant, but you should never let the soil get completely dry.

When grown as a houseplant, water it throughly once the soil is dry. Do not let the soil dry out completely for long.

Temperature and Humidity

This plant can be kept outside only in tropical areas, as it will not tolerate temperatures below 50 degrees Fahrenheit. Indoors, it prefers temperatures between 60 and 85 Fahrenheit. It also prefers high humidity. If you have an indoor container plant, you may want to place it near a humidifer.

Fertilizer

Fertilize three times per year in the spring, summer, and fall. Use organic, granular fertilizer. Or, you can fertilize more frequently with an evenly balanced diluted liquid fertilizer. For the amount to use, follow the product label instructions.

Propagating the Autograph Tree

The autograph tree can be grown fairly easily from stem cuttings, which is the recommended method of propagation.

1. Using sharp pruners, cut a couple of strong stems just below the buds, about four to six inches in length.
2. Strip the cut end of the stems of its leaves. Make sure that the top has at least a couple of healthy leaves.
3. Fill a one-gallon container with potting mix. Using a pencil or a stick, poke holes in the soil, one for each cutting. Insert about one-third of the stem into the soil. Water it well until the soil is evenly moist.
4. Keep the pot in a warm, moist place and water it regularly so it never dries out.
5. New growth is an indicator that the cutting has developed roots. If both cuttings have rooted, keep the stronger one and cut the other one at ground level (do not pull it out, or you risk damaging the tender roots of the other plant).
6. If you intend to plant the autograph tree in the landscape, leave the new tree in the container until it has grown to at least 12 inches.

Potting and Repotting

Due to its quick growth,an autograph tree can often overgrow its indoor container. If you notice roots growing out of the drainage holes at the bottom of the pot, then it's time to repot. To do so, lift out the root ball as a whole and move to a larger container (about two inches wider than the previous container) that can accommodate the root system. Use fresh soil of the same type that the plant was previously growing in.

As the plant matures, it may become too large to be kept in containers at all unless it is well-pruned. If the climate is suitable, large plants can be replanted outdoors.

Overwintering

The autograph tree is a tropical plant that does not tolerate frost. If you live in a climate where winter temperatures, even occasionally, fall below freezing, growing it in the landscape is not an option. Container-grown plants need to be brought indoors and kept as a houseplant when the temperature drops below 50 degrees Fahrenheit.

Common Pests

While the autograph tree is generally not prone to serious pests or diseases, it can get scale, mealybugs, aphids, or spider mites. Use insecticidal soap as needed.

From: thespruce