Propagation - Bulbs
There are several methods of propagating bulbs e.g. seeds, offsets,bulbils,scaling and chipping.
The most obvious method is to sow seeds of the species, however the resultant plants may not come true to the parent as is the case with many seed sown species, plus they may take several years to come into flower.
Collect ripe seed after flowering, fill pots with proprietary seed compost, soak the compost thoroughly, and sow the seed thinly on the surface of the compost.
Cover lightly with sifted compost and top off with a thin layer of grit
Pot up seedlings into 75mm (3”) pots in their second year and grow on in a coldframe.
Depending upon species it may take up to seven years for the bulbs to reach flowering size.
On reaching this size treat the species as you would with commercially acquired bulbs.
Some bulbous species e.g. Tulips and Lilies produce offsets, these can be removed when bulbs are lifted in summer, these will produce plants identical to the parent plant.
Detach the offsets, dust or wash them with a fungicide then pot them up in suitable size pots of potting compost with added sand / grit.
Place in a cold frame to grow on, dependent on size of offset, and the species, they may take up to five years to flower.
Larger, hardy offsets can be replanted out in the open ground or nursery bed immediately.
Bulbs can be forced to produce offsets but at the expense of flowers.
This is done making a notch in the base plate of the bulb/s then planting the bulb/s quite shallow.
The offsets will appear from the wound in the base plate this, and with the shallow planting will allow offsets to develop quicker.
The ripe bulbils part readily from the stems and should be sown in well-drained compost.
Lightly press them into the surface of the compost, space them about 25mm (1”) then leave them until there are signs of rooting then cover with 12mm (1/2”) of compost.
The following spring plant them out into a nursery bed to mature to flowering size.
The following spring after that plant out into their final quarters.
Bulb scales provide an ideal method of increasing hybrid lilies.
If you only want a few extra plants, scrape away the soil from the base of the stems so that the bulb is exposed and detach a few scales, ensuring that each scale has a piece of the base plate attached.
In the latter case, after the foliage dies down circa Week 35, select large, firm bulbs and trim off their tops and roots, and remove the brown outer skins to expose the overlapping scales radiating from the basal plate.
Snap off as many individual scales as are needed from the bulb, ensuring that it ends up with a piece of basal plate on it, as this is where the new growth will come from.
If the scales are somewhat limp cut them off with a sharp, clean, sterilized knife.
Replant the parent bulb on completion of this task.
Lightly dust the scales with anti-fungal powder,or wash them in a fungicidal solution.
Insert the scales almost to their tips in pans or trays filled with sandy compost.
When the new leaf is 75-100mm long, pot them up singly into 75mm pots, and grow them on in a cold frame.
Alternatively,remove the scales as described above and place them in a plastic bag containing a 50:50 mix of slightly damp compost and perlite, ,inflate the bag, seal the top and keep in a warm place e.g. an airing cupboard.
It may take up to three months for tiny bulbils to form on the chips, when they do, plant them up individually into 75mm (3") pots and grow them on at a temperature of 10°C (50°F).
They should produce leaves the following year.
Later in the year once the leaves have died back, pot them up and grow them on for another couple of years before planting them out into their final quarters.
Chipping is similar to scaling and is more suitable for bulbs such as Chionodoxa, Narcissus, and Hippeastrums.
After the foliage has died down, select large, firm bulbs and trim off their tops and roots, and remove the brown outer skins.
With a clean sterilised sharp knife cut the bulbs lengthways into segments or 'chips' ensuring that a piece of the basal plate remains on each segment.
The size of these segments is subject to the size of the bulb.
For example a narcissus sized bulb should be cut into four segments whereas a bulb of hippeastrum size may be cut into eight.
Soak the chips in a fungicide solution, then place them in a plastic bag part filled with some damp vermiculite.
Inflate the bag, seal the top and place it in a warm dark place, and maintain a temperature of 21° C (70° F),
It may take up to three months for tiny bulbils to form on the chips.
After the bulbils form, plant them up into individual 50 mm (2") pots and grow them on at a temperature of 10°C (50°F).
They should produce leaves the following year.
Allow the leaves to die back, pot them up if necessary and grow on for another couple of years before planting them out into their final quarters.