A little checklist to help you with the process of planting your begonia bulbs.
Who says spring says this is THE time to plant your begonia bulbs!
Here are some tips to help you see more clearly and especially to have beautiful flowers when the time comes.
When to leave your bulbs?
In March and early April, it's time to wake up the sleeping plants, especially the tender bulbs that you placed in the basement for the winter: cannas, callas, tuberous begonias, caladiums, dahlias, gladioli, alocasias, etc. and also any pelargonium (geranium) that you have put to sleep.
How to do
If you have kept your bulbs in a pot, simply place the container in a sunny and relatively warm location (a normal indoor temperature is very adequate) and start watering. Gently at first, because the plant has no roots yet: so hardly wet the soil the first time. But as it starts growing again, increase the amount of water and the frequency of watering. Once the plant is in full growth, water abundantly, enough to moisten the whole root ball, then wait until the soil is dry before watering again.
If the bulb has been kept bare, put it in a slightly humid soil. Begonia tubers prefer to be barely buried during recovery: cover them only with 1 cm of potting soil. For the others, place the bulb so as to cover it with 5 cm of potting soil. (When transplanting in open ground at the end of May or in June, you can adjust the depth according to the table above). Still, little watering will be required at first, as the bulb has no roots yet, but as the plant begins to grow, the soil will dry out more and more quickly and the frequency of watering should be increased by consequence, according to the golden rule of watering.
When exactly do you leave your plants?
Some of the plants mentioned here like to enjoy a long growing period. They can be potted in March or early April. This is particularly the case for alocasias, tuberous begonias, caladiums, cannas and pelargoniums. But others are faster growing: potting them only 4 to 6 weeks before the last frost (here is a list of dates of the last frost for Quebec), otherwise they tend to become too large and stale in the house. These include dahlia and gladiolus. Calla (Zantedeschia) can even bloom on the windowsill rather than in the garden if you plant it too early, so ... wait a bit before potting it.