I'd like to get some input on the group here on when it's best to
water and fertilize established bulbs (bulbs that have grown and
bloomed for at least one year). I understand it makes sense to add a
little fertilizer and water to a new bulb planting.

My particular bulbs are daffodils and bearded iris. Technically
bearded iris isn't a bulb, but I suppose this could apply to any
perennial.

I've read arguments that go both ways.

One says don't water or fertilize in the fall because plants go
dormant then, and the added fertilizer might encourage the plant to
stay active, and the added moisture might cause the dormant bulb to
rot. So it should be done in the spring as soon as new growth starts.

I've heard arguments that say that once a bulb starts growing in the
spring, it will not absorb any water or fertilizer applied to it at
that point and for the rest of the season, so it should be done in the
fall.

I've read that most bulbs (tulips, daffodils, etc.) are members of the
lily family and originate in mountainous areas of the mediterranean.
There they are only active in the wet spring, then go dormant for dry
summers and freezing winters. The Dutch/German hybrids that are
available today have inherited this behavior.

So it seems to me that if the bulb is dormant in the fall, it wouldn't
make sense to fertilize until very early spring, say April 1.

What do you think?

On Fri, 08 Aug 2003 01:28:14 -0400, Pelvis Popcan
wrote:

I'd like to get some input on the group here on when it's best to
water and fertilize established bulbs (bulbs that have grown and
bloomed for at least one year). I understand it makes sense to add a
little fertilizer and water to a new bulb planting.

My particular bulbs are daffodils and bearded iris. Technically
bearded iris isn't a bulb, but I suppose this could apply to any
perennial.

I fertilize daffodils in the spring when they are growing. A search on

iris fertilize

and a brief look at some references says that's the time to fertilize
iris, too.

I'll state up front that this is hearsay, so don't jump on me because I
don't have documentation.

A friend went to a lecture by at Brent and Becky's Bulbs, a well respected
bulb nursery and vendor. The owner said she had discovered through her own
trials that it was beneficial to fertilize established clumps of daffodils
in the fall, when root growth was taking place. She said she was able to
delay or avoid dividing the clumps with fall fertilization, and she got
abundant bloom.

I have a lot of daffodils that have been in place for almost 20 years, and
for a variety of reasons I am loathe to dig and divide them. I tried fall
fertilization, and have noticed a definite increase in bloom count.

For what it's worth,
Sue

Zone 6, Southcentral PA

Thanks for the input! So the bulb is NOT dormant in the fall then, as
root growth is taking place.

It probably wouldn't hurt to do the Iris then as well I'm betting.



"SugarChile" wrote:

I'll state up front that this is hearsay, so don't jump on me because I
don't have documentation.

A friend went to a lecture by at Brent and Becky's Bulbs, a well respected
bulb nursery and vendor. The owner said she had discovered through her own
trials that it was beneficial to fertilize established clumps of daffodils
in the fall, when root growth was taking place. She said she was able to
delay or avoid dividing the clumps with fall fertilization, and she got
abundant bloom.

I have a lot of daffodils that have been in place for almost 20 years, and
for a variety of reasons I am loathe to dig and divide them. I tried fall
fertilization, and have noticed a definite increase in bloom count.

For what it's worth,
Sue

Zone 6, Southcentral PA

"Pelvis Popcan" wrote in message
...
Thanks for the input! So the bulb is NOT dormant in the fall then, as
root growth is taking place.

That's correct. The root growth actually starts in late summer, as I've
found to my bemusement when I've been late to dig and divide. This is also
why new bulbs are planted in the fall, so they have time to develope roots
before winter sets in.


It probably wouldn't hurt to do the Iris then as well I'm betting.

Well, I wouldn't be too quick to take that leap of faith.....These are two
very different types of plants we're talking about. The daffodils are true
bulbs, and the iris are rhizomes. The daffodils don't have foliage in the
fall, so there's no danger of pushing them into green growth that won't
harden off properly. The iris do have top growth, and need to go dormant,
so I think that would contraindicate fertilization. As I understand it,
irises shouldn't be heavily fertilized at all--it can make them more
susceptible to borers and rot--but I'm not the iris expert, perhaps someone
else will chime in here.

Cheers,
Sue