Tulips have small leaves and do not flower

Question

In my garden I preserve some "wild" tulips. I say "wild" because they were planted many years ago by some ancestor of mine, I believe around late 1700-beginning of 1800. They are of a quite raw quality, not as beautiful as modern hybrids. They have long leaves, very thin, like if they were made of paper, red flowers with cuspid-like petals, and they flower very early, about 1 month before the other tulips.

Here's a picture of them: http://www.panoramio.com/photo/105948977

During time, they spread around all the garden. The point is that I notice that many of them are much smaller then usual and do NOT flower.

Is it a genetical issue (in what they have never been mixed)? Or just a question of exposure to the sun, soil, of some other kind of environmental condition (bulbs are very very deep in the ground, maybe more then 1 m: think that in the same place, my granmother used to work the ground to plant tomatoes, but bulbs were deeper!)? Or perhaps they just belong to joung generations?

In any case, is there a way to make them flower?

I already checked many questions, such as Should I keep tulip bulbs that didn't flower this year, or replace them with new? , but they seem not to exactly address my problem.

Thanks!

Answer 1

They might be species tulips rather than hybrids, although I'm not sure which - the pic's a little dark to see detail (looking for darker blotches at the base of the flowers). Many species tulips increase by seed naturally, some by stolons, but all like exposure to sun so that they bake a bit in the ground in summer, and any tulip which has spread itself by seed or offset will not flower for between 4-8 years, depending on the variety. If some of your naturally spread tulips have grown in cooler, shadier areas, that might explain some of the trouble, but the length of time between initial growth and actually flowering needs to be taken into account. The level of nutrients available while the leaves are present also makes a difference, because that's when the plant is gathering sufficient energy to swell the size of its bulb, over time, and eventually to create a flower that will arrive the following year, so it might be worth fertilizing those you know are not yet flowering during the time the leaves are present. You could apply a proprietary balanced chemical feed, or simply enrich the soil by adding humus rich materials to encourage the bulbs to grow on well.

The other alternative is to dig up the ones which haven't flowered and are shorter and not doing well and grow them on in pots, where you can control the conditions better, then plant out after they've flowered the first time.