Problems with Tulips and Hyacinths

The garden I have planted them in is about 10x10 and is surrounded by a brick wall. The soil is decomposed granite (gritty, and heavier and rockier than sand) that had peat moss mixed in about 10 years ago. Last year (Fall 2004/Spring 2005) is the first year I had planted anything there. I bought bulbs from several different sources. The daffodils and hyacinths did great, the tulips never bloomed and a few only put up a couple of really short leaves. Once all the leaves had yellowed (sometime in May), I dug up the tulips and planted gladiolus. The glads didn't come up so I finally bought one of those at home soil tests and tested the soil. Potassium and phosphorus were fine, and the pH was about 7. There was absolutely no nitrogen in the soil (I figure it was used up as the peat moss decayed). I started fertilizing with nitrogen, and in August the glads finally came up, and a few of them even bloomed.

The soil tests I ran in the fall showed that there was now plenty of nitrogen in the soil, although the pH had dropped to 6.5. I replanted the tulips I had dug up in the spring and bought some new hyacinths, daffodils, and tulips. Like last spring, the daffodils (old and new) are doing great. The old hyacinths are doing fine, but the new ones are partially underground when they bloom. I can see blooms about half an inch above the ground, and the leaves had only come up and inch or so. I dug down, pulled back the leaves, and the blooms were trying to open underground. I thought maybe I had planted them deep, so I dug one up and it was about 7 inches deep. A little deep, but not enough that I would think they would have trouble coming up. The replanted tulips are blooming, but the new tulips are only putting out one or two leaves, and none of the early tulips have even come up. I ran soil tests again, and everything was fine but the pH had dropped to 6.

I did have an unusually warm winter, and the brick wall would have moderated the temperature in the garden. Could that be part of the problem? Could the dropping pH be the problem? Is there something else I am missing?

-Winnie

First of all, pH home tests are notoriously unreliable. pH values from 5.0 -8.0 are suitable for most spring flowering bulbs so I do not think this is the case. Secondly, soil tests can not reliabily test for nitrogen either. If you only fertilize with nitrogen, chances are that you will not get blooms because too much nitrogen can surpress flowering.

Finally, peatmoss sphagnum does not rob the soil. It is in a very decomposed stage where it will not rob nitrogen. Fresh wooden material will rob nitrogen for example.

Ok here is what I would do. STOP TESTING THE SOIL.

I suspect your soil is very heavy and therefore you should try something to lighten it.
If you can find 10-15 bags of composted forest products at home depot (or buy 1/2 cubic yard of compost from a landscaper) and mix this thoroughly into the soil. You can also use 10 bags compost + 10 bags builders sand (not playsand which is too fine, but builders sand.. the yellow rough stuff).

Secondly, stop digging up your bulbs. They usually start to grow under ground -- that is normal. Plants will flower at a certain height. Sometimes, lack of cooling period can make tulips flower at short height. To counter act this, mulch the ground in early winter AFTER A HEAVY FREEZE (not before). This helps keep the ground uniformly cold (not warm) which is not important with spring flowering bulbs.

Instead of trying to match up your soil test, I recommend that you buy a bag of 5-10-10, 10-10-10, 10-20-20 fertilizer, etc. Then fertilize in fall at time of planting and twice in spring: once when the bulbs stick their heads above ground, and second time when they flower.

The soil is not heavy. It has the same gritty texture as the rest of the soil in my yard (and all those plants are doing well). It drains fairly quickly, but even in August holds enough moisture that I am not watering everyday. And is loose enough that I can dig in it with my hands (if I don't mind getting stones under my fingernails, that is :-)

I have been using a balanced, general purpose fertilizer when planting bulbs, when they first come up, and then once after they've flowered. I only used the nitrogen fertilizer 3-4 times, and stopped once plants started growing. When I say that the soil test showed no nitrogen, I mean it showed no color change what so ever. I know the home tests are somewhat inaccurate, so I did run it multiple times with different soil samples. I also ran the soil test on soil from another area in my yard, and it showed plenty of nitrogen in the soil. Also, I am certain that it was low in nitrogen because not only did the glads (after being in the ground for over 3 months) finally broke the surface about a month after I started fertilizing, but the number of weeds exploded. It may not have been the peat moss (although that was the only think I could think of), but something did rob the soil of its nitrogen.

I will consider mulching the ground next winter. But I am still confused why the 30+ hyacinths I planted Fall 2004 did fine, and all the new hyacinths (and only the new hyacinths) bloomed while still underground. And why the tulips that refused to put out more than leaves last spring are blooming while the new tulips are only putting out 1 or 2 leaves. I actually expected the opposite because people keep telling me that tulips are only good for one year. I considered that it may have been the bulbs, but (for both years) I bought hyacinths and tulips from multiple sources. If the problem was the bulbs, I would expect one of the varieties of hyacinths I bought this year to be having problems, not all 3 varieties (each from a different store) to be having problems. Same thing with the tulips.