When planting, dig a hole that is two to three times as wide as the root ball and six inches deeper than the height of the root ball. If your soil is heavy clay or sand, amend it with a planting mix or compost. Water the new plant well and place a two-inch layer of organic mulch around it, but be sure to keep the mulch a few inches away from the base of the plant to prevent rot.
Light
Shrubs in the threadleaf group generally want full sun (but only partial sun at the southern end of their range). If the plant doesn’t receive enough sun you might not see as much of the desired golden colors and the shrub foliage might get sparse and leggy. In warmer areas, a spot that gets morning sun but afternoon shade is a good choice.
Soil
These shrubs do well in a variety of soil types if there is good drainage. If you have sandy soil you might need to amend it with organic matter such as compost. They generally prefer acidic soils, but check for the specifics of the variety you will be planting.
Water
The ground should be kept evenly moist, often requiring watering once a week in summer until the plants becomes established. Once established, they will suffer if overwatered. In general, established shrubs do not need to be irrigated. These shrubs are drought-tolerant and you only need to give them extra watering during prolonged dry spells. A three- to four-inch layer of mulch can help retain moisture in the soil, especially if they are placed in a spot where the soil dries out quickly and doesn’t receive effective rainfall.
Temperature and Humidity
Different varieties of threadleaf false cypress have slightly different hardiness zones. Do some research to learn the varieties that do best in your local area. Generally, these plants can handle summer heat without too much fuss. They do appreciate some protection from strong winds, however.
Fertilizer
Threadleaf false cypress can benefit from fertilizer in the early spring. While established plants can do fine without fertilization, fertilizing will help them produce the best color. A younger plant in which you want to encourage growth might do best with a fertilizer such as 10-10-10, while established plants that are not growing as much could use a 4-8-8 fertilizer. For the amount to use, follow the product label instructions.
Types of Threadleaf False Cypress
‘Golden Mop’ is a compact variety, two to three feet tall and wide, that is suitable for USDA plant hardiness zones 5 to 8. They bear scaly leaves that keep their golden color, provided the shrub receives enough sun. It can get winter burn in cold climates. ‘Filifera Aurea Nana’ grows four feet tall and wide and is suitable for planting in zones 4 to 9. The new growth is golden yellow and retains its color during the growing season before fading in autumn. ‘Sungold’ is a large variety that can reach up to 30 feet tall. It is suitable for planting in zones 3 to 7. Foliage emerges as bright gold and matures to lime green. This shrub does not keep its color quite as well through summer as does ‘Golden Mop’, but it does a better job of avoiding winter burn. ‘King’s Gold’ is suitable for planting zones 4 to 8. It retains its golden color through the summer if it is grown in full sun six to eight hours per day.
Pruning
This shrub requires very little pruning and you should avoid doing so if you want to keep its unique shape and foliage. Heavy pruning will ruin its unique appearance; thus shrub looks best when it’s unpruned. You can, however, remove dead, damaged, or diseased branches at any time. If you must prune for shaping and to reduce its size, do so in the spring before new growth emerges.
Propagating Threadleaf False Cypress
Threadleaf false cypress can be propagated easily through hardwood cuttings. Here’s how:
How to Grow Threadleaf False Cypress From Seed
If you’re patient, you can propagate threadleaf false cypress from seed. Follow these steps:
Potting and Repotting Threadleaf False Cypress
Threadleaf false cypress varieties can be grown as container plants. Choose a smaller cultivar and a container that will allow it to grow for two to three years before needing to be placed in a larger container. The right size container is six inches greater diameter than the root ball for varieties that grow slowly.
Overwintering
Threadleaf false cypress is extremely cold hardy. If you have a potted cypress and you would like to give it a little protection in winter, simply put the container closer to your house or another structure protected from wind.
Common Pests and Plant Diseases
The threadleaf false cypress is fairly trouble-free with only the occasional spider mite attacking the foliage, turning it yellow. Black vine weevils sometimes feed on leaves and bark and their larvae feed on deep roots. Lay a cloth under the tree and gently shake the branches to catch these insects that tend to fall off easily. Scale insects may also appear because they like to suck on the juice of the cypress needles. A blight fungus may land on a younger tree’s twigs and foliage causing tips to turn brown and die. Trees over five years old seem to survive blight on their own and with little damage.
