How deep should a bamboo planter be?

When selecting a planter for bamboo, one of the most important considerations is depth. Bamboo has a vigorous root system that grows both deep and wide. Choosing a planter that is too shallow will restrict the roots and prevent the bamboo from thriving. Generally, bamboo planters should be at least 2 feet deep to provide enough room for root establishment and growth. However, the ideal depth depends on the type of bamboo you are growing and your climate. In this article, we will discuss optimal planter depths for different bamboo types and what factors impact how deep bamboo planters should be.

How Deep do Bamboo Roots Grow?

Bamboo plants develop two main types of roots – rhizomes and feeder roots. Rhizomes are the thick, spreading roots that form the root structure. Feeder roots branch out from the rhizomes to take in water and nutrients. Bamboo rhizomes can grow 6 feet deep or more in ideal conditions. However, most rhizome and feeder root growth occurs in the top 12-18 inches of soil.

The depth bamboo roots reach depends on:

• Type of bamboo – Running bamboos produce more aggressive rhizome growth than clumping types.
• Soil conditions – Roots grow deeper in loose, well-draining soil.
• Climate – Roots grow deeper in warmer climates with more favorable soil temperatures.
• Maturity – As bamboo matures over time, the root system expands and goes deeper.

While bamboo roots have the potential for deep growth, providing adequate depth for the first 12-18 inches of feeder roots is most critical.

Recommended Minimum Planter Depths

Most bamboo species require a container depth of at least 24 inches. This allows for sufficient establishment and growth of the feeder root network in the top foot or so of soil. It also gives rhizomes room to spread out without becoming root bound.

Here are the recommended minimum planter depths for common bamboo types:

Bamboo Type	Minimum Planter Depth
Clumping (Fargesia)	24 inches
Clumping (Bambusa, Chusquea)	24 inches
Running (Phyllostachys)	24-36 inches
Timber/Large species	36+ inches

As shown, running bamboos require the deepest containers – at least 36 inches is best. Small clumping bamboos can thrive in 24 inch pots. And large timber bamboo species need huge planters, sometimes 5 feet or more in depth.

Soil Volume for Bamboo Growth

In addition to depth, bamboo also requires sufficient soil volume for the plant’s size and root mass. As a general guideline, you need at least:

• 10 gallons of soil for smaller varieties up to 4 feet tall.
• 25 gallons of soil for mid-sized bamboos up to 10 feet tall.
• 50+ gallons for large timber bamboo plants.

Use large grow bags, wooden boxes, and planter beds instead of traditional containers. Make sure the planter allows for adequate drainage too.

Increasing Planter Depth Over Time

As bamboo matures, you may need to increase container depth to accommodate root expansion. Monitor signs of root bound such as slow growth and yellowing leaves. When rhizomes start emerging from the drainage holes, it’s time to repot in a deeper container.

You can also set the pot on risers or bury it partially in the ground. Just make sure at least 2 inches of the container rim remains above ground. Gradually increase pot depth over years until you reach the maximum dimensions.

Ideal Soil for Deep Bamboo Planters

Well-draining soil is key for deep bamboo planters. Wet soils will lead to root rot. Use a potting mix of:

• 1 part loam
• 1 part compost or leaf mold
• 1 part coarse sand or perlite

For in-ground planters, amend native soil with compost and sand to improve drainage. Adding a gravel layer at the bottom of planters also improves drainage.

Watering and Fertilizing Deep Bamboo Planters

Proper watering and fertilizing ensures bamboo roots thrive at all depths.

Watering Tips:

• Water thoroughly until it drains from holes after soil is partly dry.
• Avoid frequent shallow watering which encourages shallow roots.
• Water in the morning and allow soil to partially dry before watering again.

Fertilizing Tips:

• Use a balanced liquid fertilizer every 2-3 weeks during the growing season.
• Layer compost or slow-release pellets in bottom of planter before planting.
• Top dress with compost or organic fertilizer once per year.

These practices moisten deep roots and provide nutrients for deep growth.

Providing Bamboo Roots Oxygen

Proper aeration is also critical for deep root function. Here are some tips:

• Make sure soil mix includes sand, perlite or gravel.
• Avoid compacting wet soils during planting.
• Top dress with mulch to prevent soil from crusting.
• Repot bamboo every 2-3 years to refresh aeration.
• Consider installing an aeration pipe system in extra deep planters.

Good drainage and aeration encourages vigorous feeder root growth through the soil profile.

Choosing the Right Planter Shape

In addition to depth, the shape of bamboo planters also matters.

Round planters are best for encouraging descending root growth. The rounded sides guide roots downwards. But round pots limit spread of rhizomes.

Rectangular planters allow rhizomes to extend farther outward. But rhizomes may circle more at the bottom.

Oblong planters offer a compromise – room for rhizome spread and downward root growth.

Standard round and square planters are fine for smaller bamboo varieties. Use oblong grow boxes, beds or landscape plantings for larger running types needing extensive root space.

Outdoor Bamboo Planting Depth

When planting bamboo directly in the ground, follow these guidelines:

• Dig shallow rhizome barrier around planting area.
• Excavate planting hole at least 2 feet deep and wide.
• Amend backfill soil with compost and sand.
• Build raised planting bed for improved drainage.

For temperate regions with freezing winters, don’t plant bamboo deeper than 12-18 inches. Planting too deep means rhizomes won’t harden off properly in winter.

Preventing Bamboo Rhizomes from Growing Under paving

Bamboo rhizome growth can damage pavement and concrete areas. To prevent this:

• Install thick plastic rhizome barrier along edges before planting.
• Use clumping bamboo varieties instead of running types.
• Plant bamboo at least 3 feet away from paving edge.
• Annually prune back rhizomes escaping past barriers.

Catching escaped rhizomes early before extensive growth under paving helps reduce damage.

Conclusion

Providing adequate depth is crucial for bamboo planters to allow rhizome spread and healthy root function. Follow these guidelines when selecting bamboo planters:

• Choose at least 24 inch minimum depth for most bamboos.
• Use larger 36+ inch deep planters for running bamboo.
• Allow for adequate soil volume based on bamboo size.
• Increase depth gradually as bamboo matures.
• Promote drainage and aeration in deep planters.

With the proper depth and growing conditions, bamboo roots will flourish and provide the plant with vigor, size, and strength. Careful planning when selecting bamboo planters ensures your plant thrives for many years.