I live in Ottawa and never fertilize my tulips. Most of the storing of energy goes on in the fall. Right now the soil, light and warmth are more like a wake up signal than fuel.
If you are planting exotic tulips like the double fringed or the parrot tulips these are not as tough as the Darwin hybrids. All tulips can benefit from these cultivation tips:
- deadhead them to prevent the formation of seeds
- do not cut back the foliage until they have died down to the ground
- plant them deep: six inches, eight inches, a foot if you have the soil. Ottawa winters are unpredictable at best. Planting deep prevents some of the types from having the main bulb die and growing many little bulbs which take years to flower. Deep insulates from rapid temperature changes and squirrels.
You can find thousands of web sites and companies promoting bone meal as the extra ingredient tulips just have to have but research has shown this is not true for most gardens.
To summarize the research
- Bone meal supplies high levels of phosphorus and calcium, elements that are rarely limiting in
- Phosphorus, from bone meal or other sources, does not “stimulate” plant growth; it is only a mineral, not a plant growth regulator.
- High levels of phosphorus, from bone meal or other sources, will inhibit growth of mycorrhizal fungi.
- Without mycorrhizal partners, plants must put additional resources into root growth at the expense of other tissues and functions.
- Before you add any supplementary nutrients to your landscape, have a complete soil test performed first.
Good preparation of the planting area, as you have done already, is all that is required for most bulbs.