How to multiply Agave plants
Multiply Agave by vegetative growth
The most simple method to multiply Agave plants is by cutting of young plants from the mother plant. Use a sharp knive and make a horizontal cut approximately 3 cm beneath the beginning of the lowest leaf. Only cut plants which have developed in a plant with several leaves. Leave the cutting for two weeks en then put it in dry soil for root formation.
Multiply Agave by seed
Agave germination from seed is not difficult. Depending on species Agave flowers when it is 7-25 years of age (if plant development was optimal). When the plant does not flower within this period it can take many years before it does. Agave plants are sometimes called â€œCentury Plantsâ€ for a reason. After flowering fruit will develop. Development and ripening of the fruits takes about nine months. In nature where it is usually warmer this period could be shorter. Also without pollination sometimes fruit will develop. However the empty seeds in these fruits will not be fertile and will not germinate. After pollination the fruits are best harvest just before they fall from the plant or when they start looking a little dry. The year following harvest is the best time to sow and germinate the Agave seeds. Most of the time young plants (bulbills) develop on the old flowering stems. They are easily cut off and rooted as we will discuss later in this Agave article.
In practice Agave seed is bought in winter and early spring are sown. The best period for germinating the seeds is June (in Europe). During this month Agave seed can be sown and germinated with the heat and light of the sun. Offcourse you could sow earlier in the year but you will need artificial light and heat. Seeds will lose their viability over time. For germinating Agave seeds I use the following mix with success: 50% regular potting soil, 25% coarse sand, 25% crushed lava rocks or clay granulate. Put this soil mix in a container or seedtray and make the surface of the soil smooth. Do not press the soil with your hand or anything else. You want to keep an open structure for proper water drainage and air circulation. Sow the seeds 0.5 -1 cm from each other and apply a top layer of 3-5 mm fine grit or coarse sand (particle diameter not larger than 4 mm). Keep moist but not soaking wet until the seeds germinate. The first seeds usually germinate approximately after a week. The other seeds will germinate in the following weeks. After germination increase ventilation. Provide good light but supply shading against intense sunlight when needed from may until august. A germination rate of 100% is seldom achieved. Germination rates vary between Agave species. Usually rates of 50% to 90% are reached. There is no need to use desinfectants during seed germination. Use a proper germination medium and pay good attention to the combination of temperature and watering regime. The first month after germination of the Agave plants the soil is kept rather moist. In the first three months night temperatures may not drop below 10 degrees Celsius while day temperatures (created by sunlight) may reach upto 35 degrees Celsius without problems. Approximately 5 weeks after germination water regime must be changed. Do not keep the seedlings continuously moist but let the soil dry during waterings. Water once a week. Do not water if the soil is still moist.
Watering can be done from the top or from beneath by soaking. From the end of September start giving less water, once in 14 days. In October we start to prepare the plants for winter where almost no water is given. The American Agave species, when kept dry, can resist winter temperatures of some degrees Celsius above freezing. Some species, like Agave parryi and parryi varieties, can even endure several degrees Celsius below freezing if their roots are kept completely dry. Agave species native to regions where night temperatures are higher, like the coastal regions of the Caribbean, must be kept at a minimum temperature of 10 degrees Celsius during winter. If you decide to keep your seedlings warm during winter (room temperature) then water each three weeks with care. Increase the watering frequency from the end of march, depending on the number of sun hours, to once every two weeks. Also the amount of water given can be increased but only water when the soil is completely dry.
Multiply Agave by bulbils
A third method for propagating Agave plants is to use bulbils. These are small plants which often develop on the stems after flowering. This is a rather easy method. Bulbils are in fact complete Agave plants but without roots or very tiny roots. Be very careful, especially the first months, with watering after planting these bulbils. The bulbils must develop roots in their search for water and nutrients and are very sensitive to rot in this month.
Multiply Agave through underground shoots
A next and very interesting method of propagation is the following: Before reaching the surface shoots have travelled 5 to 40 cm underground. We could make 1-7 plants of these shoots! In march 2005 the author has experimented with a yellow form of Agave Americana â€˜medio-pictaâ€™, a species much sought after. The result was stunningly well. The shoots were cut in several pieces. Each piece with a minimum of one sleeping eye. After potting the eye is forced to start growing. The developing plants reach a diameter of about 7 cm after approximately a year. And, the most important thing, they all keep the color combination of the mother plant.
Agave propagation by cloning
Another form of propagating Agave is by cloning. This technique is being used by professional growers of many different plant species. Also for Agave species, of which no seeds or cuttings are available, this is a very useful method.
Agave propagation by damaging
A final method of Agave propagation: Damage the mother plant! This can be done in several ways.
Use a razorsharp knive to make small cuts in the base of the root. In reaction some mother plants will form young plants from the cuts. In some older plants the point of growth can be cut out the core of the Agave. It can be done for most of the Agave varieties. In reaction the plant may form young plants from the leaf axil. In an experiment with Agave titanota this has resulted in 10 new plants. Some species have a tendency to develop an outgrowth of young plants from the downside of the mother plant. This can occur in young Agave plants where the growth tip is slightly cut. It works for example in Agave filifera. Unfortunately this species is offered in abundance so this method is not very attractive here. This method of propagation (it seems like cloning without a lab) could also succeed in more sought after Agave species.