Posted by Brent Wilson on 8/9/2016 to Fertilizing & Watering Tips
Nandina, commonly called heavenly bamboo or sacred bamboo by some, are immensely popular, versatile evergreen shrubs with colorful, lacy foliage that resemble...you guessed it, bamboo. When established Nandina are exceptionally drought-tolerant. Bugs aren't a problem and when planted properly they have no disease problems. Although the standard Nandina domestica grows as a tall green shrub that turns a little red in winter and produces white flower spikes and clusters of red berries, other new Nandina varieties offer different growth habits, foliage colors and don't produce flowers or berries.
When planted right, and in the right spot, Nandina plants are exceptionally versatile and easy to grow and care for.
Here's a breakdown of what you need to know for how to plant and care for Nandina plants...
Nandina is not picky about soil type, however prefers a somewhat loose, fertile and well-drained soil. As with so many other types of ornamental plants, constantly soggy or wet soil can and often will cause root rot and other harmful plant diseases.
How To Test Soil Drainage
If you are uncertain about soil drainage in the area you intend to plant your Nandina, it's well worth taking the time to test the drainage before planting. 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 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 is a measurement of the alkalinity or acidity of soil, which 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.
Nandina grow best in a moderately acid to slightly alkaline soil ranging from 6.0 to 7.5 on the pH scale. Most average garden soils fall between a pH range of 6.0 to 7.0.
If you're unsure about the pH of your soil, or whether or not it's suitable for growing Nandina, 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 testing kit or probe. 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 Sulfur, Aluminum 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.
When it comes to light, Nandina are exceptionally versatile. Plant them in sun or shade and they'll do fine. That said, foliage colors will be more intense with more sun.
Planting Nandina In The Ground
Scroll down for container planting instructions
Start by digging your planting hole at least two to three times as wide and no deeper than the rootball of your Nandina plant. 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.
Depending on the type, fertility and porosity of the native soil in the planting area it might be beneficial to amend the native soil. When planting in dense clay or other compacted soils it is beneficial to thoroughly mix in some bagged top soil and/or a good planting mix at a 50/50 ratio with the 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 fertile, loamy, well-drained soil there is no need for adding a soil amendment.
Be very careful when removing your Nandina plant from the nursery pot it was growing in. Gently try to lift the plant from the pot. If the rootball is stuck in the pot, to avoid damaging the plant, cut the container away. After having removed the plant from the container, use your fingers or a claw tool to gently loosen some feeder roots around the surface of the root ball.
When Mass Planting Dwarf Nandina Varieties
If you are mass planting Nandina plants as a groundcover over a large area, to determine how many plants you will need to fill the planting area, it is helpful to determine total square feet of the planting area. Once you have the square footage of the planting area, and have determined how far apart you will space plants, you can calculate how many plants it will take to fill the planting area. (Under the description tab on every Nandina plant page in Wilson Bros Gardens you will find spacing recommendations.)
Set and space all plants in the planting area before starting to plant. Alternatively, you can use marking paint to mark the spot where each plant will go, which is often necessary when planting on steep slopes, where plants in containers will not stay put.
If there will be more than one row of plants, begin by setting out or marking one straight row of plants. It's best to start along the edge of the planting bed making sure to space plants at a distance far enough from the edge of the planting bed to allow for future spreading. For example, plants with a recommended spacing of 24" apart should be spaced at least 12" from the edge of the bed (or surfaced area) to the center of the plant. After setting out the first row, stagger the plants on the second row and so on until the space is filled.
If you are planting in well-drained soil set your Nandina in the planting hole so that the top edge of the rootball is at or slightly above ground level. If your soil drains slowly, holding water for an extended period of time after rainfall or irrigation, the top of the root ball should be 2 to 3 inches above ground level, as shown in the planting diagram below. 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) improve drainage, plant the root ball in a raised mound entirely above ground level, or select a different plant species more tolerant of wet soils.
After setting your Nandina in the planting hole, use one hand to hold the plant 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. If you are planting higher than ground level taper your soil mixture gradually from the top edge of the root ball to the ground level, as shown in the planting diagram above. To avoid suffocating your plant, avoid placing any soil on top of the root ball.
Step 6 (Optional)
When planting Nandina 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. Only build this berm if the soil is very well-drained. 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 the plant has established itself.
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, and to stimulate early root formation and stronger root development, you can also water you newly planted Nandina with a solution of Root Stimulator, which reduces transplant shock and promotes greener, more vigorous plants.
Spread a 1- to 2-inch layer of shredded or chipped wood mulch or a 3-4-inch layer of pine straw around the planting area to conserve moisture and to suppress weed growth. As the mulch decomposes it will add vital nutrients to the soil that your plants will appreciate. Avoid using 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 plant as this could cause the bark to rot.
Container Planting Instructions
Nandina are ideal for use in container gardens. When growing in pots they appreciate a moist but very well-drained soil. Constantly soggy soil can and often will cause root rot or other harmful plant diseases. Therefore, make sure the planting pot has a drainage hole(s) and use a quality potting soil or potting mix, or a 50/50 combination thereof for planting. You can also add some perlite or pumis at a 10 to 20% ratio to the soil mix to help with drainage.
Choose a container that is large enough to allow for 2 to 3 years of growth before shifting up to a larger size container. This might mean your planting pot would be 6 inches or more in width than the root ball of your plant. If you'll be growing other plants in the same container up the size of the container.
Container color will matter as well. Not only will you want to pick a color of container that goes well with the flower, foliage and berry colors of your Nandina, you'll also want to pick a container that matches the style of your home or other structures and 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.
Before filling your container with the soil mix, we 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 other materials in the bottom of the container lay the fabric on top of it.
Be very careful when removing your Nandina plant from the nursery pot it was growing in. Gently try to lift the plant from the pot. If it is stuck in the pot, to avoid damaging the plant, cut the container away. After having removed the plant from the container, use your fingers or a claw tool to gently loosen some feeder roots around the surface of the root ball.
Pour a small amount of your soil mixture in the bottom of the container. Set your Nandina plant 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.
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.
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 pine bark or wood chips to soil surface to help conserve moisture and prevent weed growth.
Caring For Nandina Plants
How To Fertilize Nandina
Nandina are light feeders, however will benefit from fertilization. To maintain good foliage color and support growth and overall health of the plant, feed Nandina in spring with a slow-release shrub & tree food. Alternatively, you can feed with a natural organic plant food. To avoid stimulating new growth that could be damaged by an early frost, cease fertilization of Nandina two months prior to the first frost date in your area.
Feed Nandina growing in containers as directed on product label with a timed-release or water soluble fertilizer listed for use in containers.
Soil pH - Nandina grow best in a slightly acid to slightly alkaline soil ranging from 6.0 to 7.5 on the pH scale. Most average garden soils fall between a pH range of 6.0 to 7.0.
Learn More: What is Soil pH and How To Test & Adjust It?
How To Water Nandina
Nandina are exceptionally drought tolerant when established. That said, in the absence of rainfall, young Nandina will require some moisture during the first year while establishing a root system. As with so many other plants, constantly soggy or wet soil can cause harmful root diseases and even death. So be careful not to over-water them!
Immediately after planting your Nandina deep soak the soil in the planting area, including the rootball, to a depth equal to the height of the root ball. An application of Root Stimulator will provide an extra boost to stimulate early root formation and stronger root development. Root Stimulator reduces transplant shock and promotes greener, more vigorous plants.
During First Growing Season
In average garden soil you should not have to water your newly planted Nandina every day. More often than not, this causes soggy soil conditions that can lead to root rot and other harmful plant diseases. In the absence of sufficient rainfall, water your Nandina plants only as needed to keep the rootball and surrounding soil damp to moist. Keep in mind that deep soaking less frequently, allowing the soil to dry out somewhat before watering again, is much better than splashing just a little water on the plants every day. Shrubs planted during the winter dormant season, when plants are not actively growing and evaporation is much slower, will require much less water. So, be extra careful not to overwater during winter!
When established, Nandina are exceptionally drought and will only require supplemental irrigation during a prolonged period of drought. If you see new leaves wilting or turning pale during a drought this could be a sign your plants could use a good deep soaking.
How To Prune a Nandina
Nandina do not require pruning for health or performance except to remove damaged or dead plant parts or to remove a stray branch that is spoiling the shape of the plant. Compact selections of Nandina (growing under 3 feet in height) remain tidy with little or no pruning. Sometimes, taller growing Nandina varieties will become bare at the bottom over time and pruning restores a full and compact look.
When to Prune
Any significant pruning for shape or size should be conducted in the late winter or early spring before new growth appears. Only older, neglected plants will require pruning.
How to Prune
Before new growth emerges in spring, use sharp bypass hand or lopper pruners (never hedge shears) to renew older clumps by cutting one-third of the main stalks to the ground. Do this for a total of three years and you will have restored your old Nandina. Also, remove old and weak branches to encourage new growth. Any time of year, you can cut back a branch or two to use in flower arrangements or wreaths.
Note: You can maintain a natural appearance by pruning each stalk to a different height, cutting back to a tuft of foliage.
Plant Long & Prosper!
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