How to Grow and Care for Golden Barberry

The Golden barberry bush (Berberis thunbergii 'Aurea') is a popular named cultivar of the Japanese barberry. This deciduous shrub is compact, adaptable, very hardy and shows off striking yellow foliage year-round. It produces far fewer fruits and seeds than other Japanese barberry cultivars, some of which are seriously invasive. But it might not be a good choice in gardens with young children or inquisitive pets, as the stems are thorny. The graceful arching stems with thorns can make for a good impenetrable hedge or protective screening plant to guard windows. But when using it to edge a pedestrian sidewalk, be prepared to keep it well-trimmed.

Barberry is normally planted as potted nursery specimens in spring or fall. Golden barberry has a moderate growth rate, adding about 1 foot per year. Some sources consider all species in the Berberis genus to have mild toxicity, capable of causing minor digestive upset and skin irritation. This, along with the thorns, may be why barberry shrubs are rarely eaten by deer.

Golden Barberry Care

Barberry bushes are known for being robust and versatile shrubs, and 'Aurea' is no exception. Providing this bush gets plenty of sunlight, it will thrive in most conditions, although it won't tolerate waterlogged soil. The planting technique is typical for any generic woody shrub: Dig a hole about twice as wide as the root ball, and plant the shrub at the same depth it was growing in its nursery container. Beyond, there is very little you need to do to ensure the shrub thrives.

Warning

At least 22 states, mostly in the upper Midwest and Northeast, have issued cautions or prohibitions about the invasive properties of Japanese barberry. In addition to the very vigorous self-seeding that occurs when birds eat and spread the seeds, these plants are known to form dense thickets that are very favorable to deer ticks, the primary vector for Lyme disease. In addition, these plants can actually change the soil pH in a manner that causes native plants to die away as the invader expands its colony. The 'Aurea' cultivar, while it produces far fewer fruits and seeds than other varieties, can and does spread, though at a much less aggressive rate than some of the other varieties.

Light

Doing best in full sun, this shrub also manages well in partial shade. The leaves take on their brightest coloring, however, if they get at least six hours of direct sun a day. In a shadier position, the foliage may be a greener shade, rather than the vibrant yellow associated with this bush.

Soil

The golden barberry isn't fussy when it comes to soil type. It does well in dry and moist soils. The only issue it will have is growing in soils that regularly become waterlogged. Standing water is a problem for this species, so make sure the soil is well-drained. It tolerates both acidic soils and slightly alkaline soils.

Water

This shrub is reasonably drought-tolerant and only requires a middling amount of moisture to thrive. Be careful not to water unnecessarily, as this can impact the shrub's color and vigor.

Temperature and Humidity

Hardy in USDA zones 4 to 7, this shrub will do well in both blazing summers and frigid winters. Dry and humid atmospheric conditions are equally tolerated by golden barberry, though high humidity paired with poor air circulation is a recipe for mild fungal diseases such as leaf spot.

Fertilizer

The hardy golden barberry doesn't need regular applications of fertilizer to ensure good growth. The only time you might want to use some would be in early spring, prior to the new growth starting. For established shrubs, fertilizing only every second or third year will be sufficient.

Types of Japanese Barberry

In addition to 'Aurea', Berberis thunbergii is available in a number of other named cultivars. There are many dozens of them, many with reddish foliage, others with yellow-green. These are some widely available varieties:

• 'Crimson Pygmy' is a 1- to 2-foot dwarf variety with reddish-bronze foliage.
• 'Gold Pillar' is a 3- to 4-foot plant with an upright growth habit and golden summer foliage that turns orange-red in fall.
• 'Orange Rocket' is a 4- to 5-foot plant with foliage that transitions from coral red in spring, to medium green in summer, to bright red-orange in fall.
• 'Fireball' is a dwarf, 1- to 2-foot variety with fiery red foliage from spring to fall.

In regions where barberry sales are controlled due to invasiveness, you may find that only certain cultivars that produce few seeds are available for sale. In other areas, there will be no exemptions, and Japanese barberry will be unavailable in any form.

Pruning

The golden barberry is a compact and slow-growing shrub, with a naturally rounded shape. It shouldn't require excessive pruning, but you can remove up to one-third of the old branches if you need to prune for shape or to keep it disciplined as a hedge plant. Any major pruning you do should happen in early spring as new growth is beginning. When used as a hedge, it is typical to shape the shrubs so that they are somewhat wider at the base than at the top, which allows for sunlight to reach all growth. Another technique used for barberry hedges is "pick pruning" in which open holes or columns are pruned out of the shrub to allow sunlight to penetrate down into the interior. This can be accomplished by pruning out selected older stems all the way down to ground level.

Avoid all pruning for a month or so before the first winter frost. But if necessary, some pruning can be done after winter sets in and the shrub goes dormant.

Propagating Golden Barberry

If you want to add an additional golden barberry shrubs to your garden, the best way to do this is to propagate from a cutting. That way, you are guaranteed to get a bush that can produce a very similar shade of foliage. The best time to take a cutting is in late spring after the shrub has bloomed, or you can take a semi-hardwood cutting in the summer. Here's how to do it:

1. Using sharp pruners, cut a 6-inch length from a branch that is new and healthy.
2. Remove the foliage on the bottom half of the cutting, then dip the cut end in rooting hormone.
3. Plant the cutting in a small container filled with a sandy, light potting mix—a mixture of potting soil and sand works well.
4. Place the pot in a plastic bag and keep the soil mix moist at all times. Roots should start to establish within a few weeks.
5. After roots are evident, wait two more weeks then transplant into a larger container filled with standard potting mix. Continue to grow in the pot until ready to plant it in the landscape. It can be kept growing in the pot for a full year or more, if you choose. If overwintering in a pot, move the plant to a sheltered location, such as a cold frame or porch, for the winter months.

How to Grow Golden Barberry From Seed

Collected seeds from this named cultivar usually do not "come true" to the parent plant, so seed propagation is not common. Planting from collected seeds can result in plants with a different foliage color.

If planting from purchased seeds, you will need to give them cold stratification, which is best provided by planting the seeds outdoors in the fall, in pots filled with standard potting mix. This is a slow-growing shrub with slow-germinating seeds; you may not see signs of growth until well after winter and following spring have given way to summer. Seedlings need to be kept well-watered and warm in order to grow into viable plants. As the plants get larger, you can pot them into a larger container. It's not uncommon for seed-started barberries to remain in pots for two full years before they are ready to plant in the landscape.

Again, before planting any barberry, consult local authorities on restrictions that may exist regarding the sale or cultivation of Japanese barberry.

Potting and Repotting Golden Barberry

Although it's not common, container culture is possible for golden barberry. Make sure to use a large, broad pot that can accommodate the mature size, which can be as much as 5 feet wide, with a spreading root system. These plants with their thorny stems are not fun to repot, so it's best to use a large pot right from the start. Ordinary commercial potting mix works fine as a growing medium, but potted specimens will be more frequent watering and feeding.

But these thorny plants are not a good choice for decks and patios, where people might brush against them. Be aware of this when choosing a location for a potted barberry. In colder climates, a potted barberry should be moved to a sheltered location for the colder months.

Overwintering

These are very hardy shrubs that generally don't need winter cold protection. But they can be susceptible to feeding by hungry rabbits, so typing the plant stems together and surrounding the shrub with a cage of hardware cloth, buried and staked into the ground at the bottom, is recommended.

Common Pests & Plant Diseases

Golden barberry has no notable pest and disease problems. In humid conditions, they are sometimes affected by fungal or bacterial leaf spot, and root rot can sometimes occur in very wet, soggy soils.

Occasional pest problems include aphids, webworms, and scale. These can be treated with horticultural oils—or simply ignored, as the damage is rarely serious.

How to Get Golden Barberry to Bloom

The appeal of golden barberry is the foliage color, not the flowers or berries, which are more subdued in this variety than in other cultivars. So there is generally no reason to seek improved flowering. Should it be important to you, make sure the plant is getting plenty of direct sunlight.

Common Problems With Golden Barberry

The most common complaint about Japanese barberry (the only complaint, really) is that it can become too aggressive in the landscape, since it spreads so readily by underground runners, by "layering" itself when branches simply droop and touch the ground, and by seeds that can be distributed far and wide when birds eat and digest the fruits then deposit the seeds.

This is not a plant you want growing near pedestrian traffic, as the thorny stems easily scratch and puncture skin. If you use this as a hedge along sidewalks, be prepared to prune diligently.

From: thespruce