Following the discussion Adrian and I had last week regarding which bulbs we would like to plant this autumn for our spring gardens, we thought we would share some information and a few tips with you.
Bulbs and corms for spring flowers (plant in autumn)
Autumn – sometime between September and December – is the time for planting flower bulbs. A number of them can be planted from September onwards, especially the early-flowering varieties (such as winter aconite, anemone, snowdrop, grape hyacinth and Siberian squill), narcissi/daffodils (which we want to start growing immediately after their summer rest) and hyacinths which are less sensitive to frost if they are given the opportunity to form roots before the frosts sets in. Tulips can still be planted fairly late, into December.
Storing bulbs and corms when you receive them is always risky. If at all possible, it is best to plant immediately. However, if you can’t, open the bags and put them in a not too warm, dry place; in the dark.
Planting depth is different for each type of bulb. The directions are given on the label. Planting distance has to do with the circumference of the plant. An ornamental onion such as Allium karataviense requires approx. 20 cm but smaller ones like snowdrop, glory-of-the-snow and Siberian squill require only 2 cm and should therefore, be planted in large groups (not less than 15), otherwise they won’t show to their advantage. Bulbs suitable for naturalizing will in the long run form natural clumps (narcissi/daffodils, spring snowflake, Spanish squill, snowdrop, botanical crocus).
Position – bulbous plants will seldom disappoint you. The complete plant is already present in the bulb/corm and only needs to grow. As to how far it will be able to hold its own, depends on soil and position. Sometimes the colour and/or the size of the flower will decrease. There are however, bulbs which are particularly suitable for naturalising. They should feel at home in our climate and should not be disturbed by digging. They will then behave as perennials (wild tulip, ornithogalum and snake’s-head are native plants).
Feeding bulbous plants is useful to promote good flowering. A fertilizer which doesn’t contain too much nitrogen but does contain a good deal of phosphorus – which is beneficial to good flowering.
Bulb size – It goes without saying that all bulbs will flower nicely, the smaller ones too. These smaller bulbs are particularly suitable for planting larger groups. The large bulbs can be spaced somewhat farther apart in smaller groups of at least 6.