Working seed balls with bamboo seeds

Bamboo belongs to the sweet grass family and is not only native to China, but all over the world with the exception of Europe and Antarctica. There are 47 different species with around 1200 varieties, of which only around 20 are suitable for cultivation in Central European gardens. Many of the bamboo species cultivated here only bloom about every 100 years, which is why collecting seeds and the resulting reproduction is difficult.

Not all bamboo is created equal

The real bamboo (Latin Bambusa) is rarely found in Central European gardens due to the climatic conditions. Instead, different hardy varieties of the two genera Phyllostachys (flat tube bamboo) and Fargesia (umbrella bamboo) are cultivated in this country. These are usually uncomplicated to care for, whereby the Phyllostachys species should be prevented from spreading uncontrollably by means of a special root barrier. Propagation usually takes place via division, rarely - and only possible in a few species - via cuttings.

Bamboo flowers extremely rarely

The collection of seeds and their reproduction is very difficult due to the extremely rare flowering of the two most commonly cultivated bamboo genera Phyllostachys and Fargesia. These species only bloom once every 100 years, although specific periods cannot be given. As a rule, almost all specimens of a species bloom around the same time - worldwide. The reason for this rare bloom has not yet been scientifically established, but there are suspicions: For example, through these extremely long periods of time, the plant genus ensures that certain animal species cannot specialize in eating the seeds - and thus ensure the survival of the species for sure.

Other bamboo genera and species, on the other hand, bloom more frequently, but only at intervals of at least 12 years to several decades. After the perennial flowering, many plants eventually die due to lack of nutrients, but first sow themselves. This is especially true for Fargesia, which last bloomed in the nineties or around the turn of the millennium.

Harvest bamboo seeds

When bamboo blooms, it does so over a period of around two to five years. In the meantime, the plant continues to develop new flowers in spring, but no new leaves appear. As a result, the bamboo burns and eventually dies. After fertilization, the seeds develop from these flowers and can be harvested towards the end of summer or in autumn. Unfortunately, the seeds of the more frequently blooming types of bamboo turn out to be sterile in many cases and therefore not capable of germination. First dry the self-harvested seeds for one to two days, then let them swell for a few hours in a warm water bath and plant them promptly.

Instructions for harvesting bamboo seeds

  • Harvest only possible after rare bamboo blossoms
  • Flowering occurs cyclically at intervals of several decades
  • Flowering cannot be provoked - it only helps to wait and see
  • Collect ripe seeds at the end of summer / autumn
  • Gently clean the seeds with a soft, dry cloth
  • Let the seeds dry for a day or two
Sow the seeds as freshly as possible, as they will lose their ability to germinate over time.

Buy the freshest possible seeds

This is especially true if you want to buy and sow seeds. Inquire about the flowering times of the type and variety of bamboo you want to determine the best time to buy seeds. The fresher the seeds, the higher the germination rate. The seeds of the very popular Moso giant bamboo (Latin Phyllostachys edulis or Phyllostachys pubescens) are mainly harvested in October and November, so you shouldn't necessarily buy them in autumn of the following year. There can only be fresh seeds if the bamboo species in question is currently in a flowering cycle.

Growing new bamboo plants from seeds

If you have bought bamboo seeds, you will receive the appropriate growing instructions for the species and variety. Exotic, tropical species in particular need high temperatures of over 26 ° C in order to germinate successfully. In contrast, temperatures between 16 and 24 ° C are sufficient for the bamboo species that are hardy in our country. Growing the plants from seeds is basically possible all year round, but you should ensure an adequate supply of light. To do this, place the hatchery directly next to a bright window (a south-facing window is ideal).

Tip: During the dark winter months or for growing in a dark room, the installation of a plant lamp can be useful, although you do not necessarily have to resort to expensive special lamps. Simple, warm white fluorescent tubes are sufficient for bamboo.

Prepare seeds

Before you sow the seeds, you should first let them swell for six to twelve hours - preferably overnight - in a glass of lukewarm, clean water. If you do not have a fresh seed, but an older one, you can peel it to improve the germination capacity. Of course, this does not happen in nature, but the seeds are not stored there for months or even years.

Tip: Cultivation methods vary

If you are unsure, you can also divide the existing seeds and treat them differently. In this way you can also check which cultivation method works best for you. For example, you can soak some of the seeds, some not, some seeds like cress on cotton wool, others on the other hand on sandy substrate in the greenhouse. Don't be afraid to experiment, as many types of bamboo are difficult to lure out of their hard shell when it comes to germination.

Prepare the substrate and plant containers

In terms of substrate, use sandy potting soil that is as low in nutrients as possible, but so-called seed pads (for example made from coconut fibers) are also very suitable. These only have to pre-soak in water and can then be placed in the prepared planters. You can use special growing plates, but also small pots or yoghurt pots. It is only important that the containers are thoroughly washed out and clean so that no germs or mold can destroy the germination success.

Planting and caring for seeds

Since all types of bamboo are light germinators, you must not plant the seeds directly. Instead, just lay them on the moistened substrate and in no case cover them with soil. Some advisors recommend a light covering with bird sand, but this is also not advisable due to the poor germination rate. You can put several seeds in one jar. Then care for the seeds as follows:
  • Always keep the substrate slightly moist
  • The substrate must not be wet, otherwise the seeds will rot
  • Moisten the substrate with a spray bottle
  • Keep humidity high
  • Cover the planter with cling film, a cut-off PET bottle or something similar
  • Indoor greenhouse with or without heating is also very suitable
  • Ventilate several times a day to prevent mold growth
  • Place the planter in a bright and warm place - but not in direct sunlight
These growing rules apply in principle to all types and varieties of bamboo and only vary in detail (for example with regard to the ambient temperature). The seeds germinate within one to two weeks, but depending on the species, variety, growing conditions and age, it can take several months to a year for the first soft green to develop. So if in doubt, be patient and don't throw the gun in the grain if the germination doesn't work right away.

Tip: Since young bamboo plants are very sensitive to moisture, you should actually only keep the substrate very slightly moist. The potting soil must not just dry out, otherwise germination cannot take place.

Caring for and planting seedlings

After germination, only a single cotyledon appears (and not a pair of leaves, as is the case with many other plant species). If this cotyledon can be seen and the small bamboo has already grown a bit, you can carefully separate the plants and place them in small pots with a suitable, nutrient-poor substrate. When moving, do not remove the seeds under any circumstances, but cover them with soil.

Continue to hold the plants under compressed air (i.e. under foil) and make sure that they are not exposed to direct sun for the first few months. If the substrate is finally well rooted, you can move the young plants into a larger pot with suitable bamboo soil. You can start fertilizing as soon as the first real leaflets appear. Use special bamboo fertilizer for this purpose, lawn fertilizer is also suitable (caution: choose a brand that does not destroy moss!). However, fertilize very sparingly at first.

When can the seedlings go outside?

Whether and when the young bamboo plants can go outside depends on their size, the prevailing weather conditions and, above all, on the specific species. As a rule, you should first cultivate young bamboo in pots and plant hardy species such as Fargesia and some Phyllostachys only in late spring / early summer after the last night frosts. Many other types of bamboo (including the popular Phyllostachys edulis or Moso giant bamboo as well as tropical species such as Bambusa or Dendrocalamus), on the other hand, are not winter hard and should therefore be cultivated in pots anyway. In the cold season you have to overwinter in the winter garden or similar, free of frost, but you can go outside without worrying during the summer months.