What does a clumping bamboo do during the seasons of the year?

We specialize in clumping bamboos so that is what we will cover. Running bamboo can be invasive if not managed correctly and has earned bamboo as a landscaping plant more or less of a suspect reputation. You can relax with clumping bamboos given you have an appropriate climate to plant them. No rhizome barrier is necessary, no worry.

Starting at the beginning of our traditional gardening season (Springtime), what are clumping bamboos doing? They are dropping their leaves. "Wait, I thought bamboos were evergreen?" Yes they are, they re leaf and add new branches in the spring time, as new leaves pop out, the old ones drop so you never get a naked bamboo to stare at. Running bamboos send up new shoots at this time. While everything else in your garden and landscape is going crazy, clumping bamboos grow and extend their root system, extend new branches on existing culms (or canes), and are making new leaves. This is a critical time as the water and care they receive will determine how many shoots your plant will develop for the shooting season. This is a great time to fertilize with a high nitrogen feeding and re-mulch. Mulch will make your watering more efficient, will help stabilize soil temperatures, and aid in distributing moisture around the base of your plant.

If you have an established planting, this is a good time to thin out old, small, or disfigured canes from your clump (don't thin new bamboos until their third year or so unless you have an annoying cane leaning across your sidewalk or rubbing against your house. The hot season is coming, so make sure your clump of bamboo can somewhat shade its root system so your roots don't fry! If you provide nurturing quality care to your plant, this is not as big of an issue. Mid-June is an opportune time to fertilize with a high nitrogen feeding the second time of the season.

Late June and July is prime time for new shoots! Most growers do not recommend fertilizing a bamboo while it is shooting, it tends to weaken the new growth and prevent them from developing correctly. Mostly hardy Bambusas shoot at this time with more tropical types like Dendrocalamus shooting a little later July and August. This is the most exciting time of year for clumpers! Remember, bamboo does not grow like trees or other woody plants, what you have seen so far of your bamboo will not grow any larger, taller, or thicker. Old canes just make new branches and leaves every year. New shoots push through the soil surface at the diameter they will be when the cane is at full height. What you see is a spike coming out of the ground, but what you can't see inside of it is your entire culm compressed much like a closed accordion covered by a sheath of modified leaves to protect it. The mother plant injects water and nutrients from the root system as well as nutrition from older culms into the new shoot as it grows at an astonishing pace to its full height within 5-8 weeks. Sometimes this growth can be more than a foot per day!

Be careful though, your new shoot is very soft and full of water so they can be easily broken and damaged. If you have a new shoot that is popping up where you do not want it, you can easily step on it with your foot or break it off by hand with no tools and that shoot will never grow again. Another way to do this is to wait until the shoot is about 8 inches tall then cut it at the base, peel the sheaths off, boil them, chop it up and put it in a salad!

As your new shoots extend to their full height, water is very critical at this time as well, new shoots are known to abort when not enough moisture is provided. In their native climate, they are used to monsoonal summers during shooting season, so don't back off on the water! When your shoot has reached its full height, it might decide to go ahead and send out branches and leaves, or depending on the time of the season, might wait until next spring. This is when the new culm will "harden off". The culm walls will begin to harden and become a little more sturdy. If you have a late-shooting tropical type this can be late summer/fall, some canes wait all the way through fall and winter before leafing out. This makes them a little more vulnerable to frost damage etc.

During the fall season, the new shoots establish their feeder roots getting ready to be a part of next year's shooting season. Many people fertilize for their third and final time for the year, your bamboo is exhausted! This feeding can be a little higher in phosphorous to feed the root system and help the plant fight off the frosty winter ahead. Always avoid excessive boron and salt ingredients with your bamboo feed. However, small amounts of salt and trace salt elements in time release pellets are said to aid in hardiness and give your plants a little anti-freeze treatment. Winter is dormant.