When planted right and in the right spot, Chaste Trees are one of the easiest flowering trees you'll ever grow.

Depending on your preference, Chaste Tree quickly grows into a multi or single-trunk shrub or small tree to about 10 to 20 feet tall and wide, depending on the variety. In design, I use it most often as I would a Japanese maple or crape myrtle tree: as a small focal point specimen, in groupings of three or more, or to frame in the corners of homes and other structures. When grown as a shrub chaste trees make a colorful hedge planted in staggered or straight rows. They look especially nice around garden ponds and boulders.

Here's a breakdown of what you need to know to plant a Chaste Tree...



Cultural Preferences


Soil

Chaste Trees will grow in most any average soil, including clay soils. They prefer a well-drained soil however will tolerate temporary wet conditions. Avoid planting in soil that stay constantly soggy or wet.
 

How To Test Soil Drainage 

If you are uncertain about soil drainage in the area you intend to plant your chaste tree, it's well worth taking the time to test the drainage. To test soil drainage, dig a hole 12" wide by 12" deep in the planting area. Fill the hole with water and let it drain. Then, after it drains, fill it with water again, but this time clock how long it takes to drain. In well-drained soil the water level will go down at a rate of about 1 inch an hour. A faster rate, such as in loose, sandy soil, may signal potentially dry site conditions. A slower rate indicates poor draining soil and is a caution you might need to improve drainage, plant in a raised mound or bed, or look for plants that are more tolerant of wet or boggy conditions.



Soil pH

Chaste trees grow best in an acid to slightly acid soil ranging from 6.0 to 7.0 on the pH scale. Most average garden soils fall between a pH range of 6.0 to 7.0. 


Testing Soil pH 

Soil pH is a measurement of the alkalinity or acidity of soil and is measured on a scale of 1-14, with 7 as the neutral mark. Any measurement below 7 indicates acid soil conditions, and anything above 7 indicates alkaline. If you're unsure about the pH of your soil, and whether or not it's suitable for growing chaste tree, it's a good idea to test the soil pH in the planting area. You can quickly test soil pH with an inexpensive soil pH tester probe or kit

To raise the pH (make more alkaline) you can add pelletized limestone to the soil. To lower the pH (make more acid) you can apply Soil SulfurAluminum Sulfate, or Chelated Iron. Adding organic compost to the soil or using compost as mulch can also help to increase acidity and maintain acid soil conditions.




Light Needs

Chaste trees grow and flower best in full sun. A little shade is tolerated, however the best flowering occurs with at least 6 hours or more of direct sunlight per day. The more sun the better! 




Planting A Chaste Tree In The Ground

Scroll down for container planting instructions



Step 1

Start by digging your planting hole at least three times as wide and as deep or not much deeper than the root ball of your crape myrtle. The wider the hole the better. Place native soil removed from planting hole around the perimeter of the hole, in a wheel barrow, or on a tarp.


Step 2

Depending on the type, fertility and porosity of the soil in the planting area, it may be beneficial to amend the native soil. When planting your chase tree in dense clay or other compacted soils it is beneficial to thoroughly mix in some bagged top soil or a good planting mix at a 50/50 ratio with the native soil removed from the planting hole. When planting in very sandy, quick-draining soil you might want to consider mixing in some top soil, peat moss and/or compost to help retain moisture. When planting in well-drained but moist soil of average fertility there is no need for adding a soil amendment.


Step 3

TIP:  It's beneficial to water the root ball deeply before removing your chaste tree from its container.

To remove your chaste tree from the nursery container it was growing in, firmly grasp the tree or shrub by the base of its trunk and try to gently lift and remove it from its container. If the root ball is stuck in the container either cut the container away or place the plant on it's side and tap on the side of the container to loosen the root ball. After having removed the plant from the container, use your fingers or a claw tool to loosen some feeder roots around the surface of the root ball. If root bound, you can spray the sides and bottom of the root ball with a stream of water from a garden hose. This will help to wash away some soil from the exterior of the root ball making it easier to loosen roots.


Step 4

Set your chaste tree in the planting hole so that the top edge of the root ball is at or slightly above ground level. If necessary, add some backfill soil mixture to the bottom of the hole to achieve proper planting height. 

Note:  If the soil is poorly drained (constantly soggy or wet) either improve drainage, plant the root ball in a raised mound, or select a different plant species more tolerant of wet soils. 




Step 5

After setting your chase tree in the planting hole, use one hand to hold the tree straight and your other hand to begin back-filling your soil mixture around the root ball, tamping as you go to remove air pockets. When you have filled the hole to the halfway point you can soak the soil. Then continue back-filling to the top edge of the root ball. To avoid suffocating your plant, avoid placing any soil on top of the root ball. You can place mulch on top of the root ball later. 


Step 6 (Optional)

When planting a chaste tree in a location that is far from a water source, you can use remaining soil mixture to build a water retaining berm (catch basin/doughnut) around the outside perimeter of the planting hole. This basin will help to collect water from rainfall and irrigation often reducing the need for hand-watering. The berm can be removed after a year or so when your tree has established itself.


Step 7 

Next, deeply water the planting area, including the root ball, to a depth equal to the height of the root ball. For an extra boost, to stimulate early root formation and stronger root development you can also water you newly planted chase tree with a solution of Root Stimulator, which reduces transplant shock and promotes greener, more vigorous plants.


Step 8

To conserve moisture and to suppress weed growth, apply a 1 to 2" layer of cured, shredded or chipped wood mulch or pine straw around the planting area. As the mulch decomposes it will add vital nutrients to the soil that your tree will appreciate. Avoid the use of freshly chipped or shredded wood for mulch until it has cured in a pile for at least 6 months, a year is better. Avoid placing or piling mulch directly against the base of your tree as doing so could cause the bark to rot.



Planting A Chaste Tree In A Pot


A chaste tree growing in a pot will appreciate a moist but well-drained soil. Constantly soggy or wet soil can and often will cause root rot or other harmful or deadly plant diseases. Therefore, I recommend using a quality potting soil or potting mix, or a 50/50 combination thereof in a container with a drainage hole(s). You can also add about 10% pumice or perlite to the soil mixture to help with drainage. 

Make sure to choose a container with drainage holes at the bottom and one that is large enough to allow for 2 to 3 years of growth before having to shift up to a larger size container. This might mean your planting pot would be 8 inches or more in width than the root ball of your chase tree. 

Note:  Keep in mind the wind. When planting taller growing trees in containers, wind is always a factor. Choose a pot with a low profile and make sure to place your container where it will not be exposed to high winds. Square pots tend to be more stable than round pots. You can also place a brick(s) or other heavy objects in the bottom of the container for stabilization.  

Container color will matter as well. Not only will you want to pick a container color that goes well with the flower and foliage color of your chaste tree, you'll also want to pick a container that matches the style of your home or other structures and other plants in the surrounding environment. 

Many nursery & garden centers offer a wide variety of containers to choose from. Before heading out to buy a container take pictures of your home and the surrounding environment. Doing so will help you to choose just the right color and style.



Container Planting Instructions


Step 1

Before filling your container with the soil mix, I recommend lining the bottom with shade cloth or a porous landscape fabric. This will keep the drain holes from becoming stopped up with soil. If you use stones or brick in the bottom of the pot lay the fabric on top.


Step 2

To remove your chaste tree from the nursery container it was growing in, firmly grasp the tree or shrub by the base of its trunk and try to gently lift and remove it from its container. If the root ball is stuck in the container either cut the container away or place the plant on it's side and tap on the side of the container to loosen the root ball. After having removed the plant from the container, use your fingers or a claw tool to loosen some feeder roots around the surface of the root ball. If root bound, you can spray the sides and bottom of the root ball with a stream of water from a garden hose. This will help to wash away some soil from the exterior of the root ball making it easier to loosen roots.


Step 3

Pour a small amount of your soil mixture in the bottom of the container. Set your crape myrtle in the container and make necessary adjustments by adding or removing some soil so that the top edge of the root ball will sit 1" or so below the rim of the container.




Step 4

Backfill with your potting soil around root ball, tamping as you go, until the level of potting soil is even with the top edge of root ball.


Step 5

Water thoroughly until water starts to drain from the holes in the bottom of the container. Add more potting mix if settling occurs during watering.


Step 6 (Optional)

Apply a 1/2" layer of wood chips or sphagnum moss to soil surface to help conserve moisture. You can also incorporate low growing, spreading plants in your container planting that will serve as a permanent soil cover.



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