I planted the little alliums about 15cm deep - as instructed by T&M. However, my neighbour says the sphaerocephalon and roseum should only go in about 6cm otherwise they will struggle to reach the surface of the soil! Does anyone have any advice on this? Other websites are equally vague!! Thanks very much!
with most bulbs I work on the top of the bulb should be positioned 2 x height of bulb below surface. So a 1cm bulb should have 2cm soil on top.
a 4 cm bulb should have 8cm soil on top. Tulips can be up to 6 inch deep.
I plant my purple sensations and the other monsters about 6inches deep, but i agree that the spherac....??..on ones (sorry, trouble with the spelling) are much smaller so i plant them shallowly - about an inch deep.
3 times the depth of the bulb is a good guide to go by.