Why do some hostas shrink?

[FreakyCola]

I have a bunch of hostas that are much smaller than they were last year. What causes that? I water all the time so I don't think that's a reason. I started each bed by putting lots of shredded leaves and compost in and double digging so they're all started out right.

In one bed there's a Rascal that was huge last year, at least 6' wide & this year it's about 4' wide. In same bed, but at the other end is a Fortunei Aureomarginata that has always been about 4' wide and is only about 2' this year. In another bed is another FAM that is about half what it was last year. These are just a few examples. Got any ideas?

Thanks,
Ellen

[scootersbear]

16 elements basically make plants grow. There not getting atleast 1 of them. What do the leaves look like? Specially the bottom leaves? If they are yellow it's most likely lack of iron..

[Chris_W]

The biggest reason for a hosta to shrink is lack of water at some point in time, next reason is possibly rodent damage, but they tend to really set the plants back.

Two reasons for lack of water are tree roots and simply drought, however with drought you don't tend to really see the effects until the following year. If you had a drought last year then the hostas could be smaller this year. Or conversely, if you had a lot more water last year than this year that could have caused unusually large growth last year.

Supplemental water is never quite the same as rain water. Nutrients can play a part in it, but unless you were really juicing the hostas last year (giving them extra doses of fertilizer) it shouldn't make that much of a difference.

[jgh]

There's an old saying that we are always fighting the last war. Sometimes what we see this year is really about what happened last year.

We observe a radical change in hosta size by what is above the ground, but it is really all about what is below the ground.

So putting those two things together with the comments from Scooter and Chris...

Lack of essential nutrients will indeed limit the plants growth. Lots of shredded leaves make for nice humus in the soil - but rotting brown matter can also take a lot of nitrogen out of the soil. The little organisms that eat brown matter use up nitrogen. When I mulch heavily with leaves, I also add lawn fertilizer that is mostly nitrogen, which replaces some of the nitrogen lost and speads up the breakdown.

Still - you are describing a rapid reduction in size, not a steady decline over several years. Nutrient problems usually result in a slower decline. In that case, I'd look at something more immediate. The crown and roots on these plants are almost certainly damaged, or at least smaller than they were a year ago.

Water is the obvious thing to consider. Several scenarios are possible. If the fall is very dry, plants can experience damage to the root ball. The extremities dry out and die off. The damage from the drought period doesn't show until the next year when the plant doesn't have as large a root system to build on. The reverse can also occur... a wet cold fall can result in rotting of parts of the root system. Again, in the spring the plant starts off from a smaller base. A cold, wet spring can also result in plants sitting in too much moisture for too long and rotting in the ground - this will also result in smaller plants.

I experienced shrinking hostas due to the roots of a silver maple... but the decline spread over a number of years. For mature clumps to decline this rapidly, I have to believe that something involving lack of water, too much water, cold and fungus/rot did some damage to the root systems... and most likely it was last fall and winter when the damage was done.

[FreakyCola]

Thanks for your thoughts. Hmmm.
I am very good about watering every 2-3 days if it doesn't rain. I pay close attention to the end of the season even when the leaves are brown I still water, should I cut down then? I've always done it the same so I doubt that I'm over watering.

I try to put 12-12-12 on the whole yard 2x a year, in February or March and then in the summer sometime, but the second dose usually gets forgotten. Actually I think I forgot to fertilize in Feb. the last 2 years so that could be the problem.

BUT I've noticed an increase in the chipmunk population and they have little holes in several places all over the yard. But no holes around any of the smaller hostas, so maybe that's not it either.

The hostas all look incredibly healthy, no discoloration of leaves at all. I've had a three in this same bed as the Rascal & FAM that have shrunk to almost nothing then rebounded and are back to the original size in about 3 years with no help from me. So now that I'm thinking about it, it's mostly this one bed. Hmmmm Hmmmm Hmmmm.

I don't think we had a drought last year, but I'll get out my old calendar and check. I'll also look closer at the crown & maybe dig around alittle to see what the roots look like.

I like to think they're just being gentlemen hostas, even Rascal. Rascall got so big last year you could barely see Strip Tease. I'm sure Rascal wants to see a Strip Tease so he just decided to stay littler this year! And FAM was over powering Hoosier Harmony last year so I'm sure he's just being nice & giving HH more room. Perhaps if I remove somebody so they all have more room it would help too!
Ellen

[ViolaAnn]

Your location may be very different from mine, but I would worry about watering every two or three days because if the watering is too frequent, the plant won't develop as good a root system and will become dependent on water every two or three days.

But then if you are even able to fertilize in February, a time when mine are covered with a blanket of snow, maybe what applies here doesn't apply at all where you are.

Ann

[FreakyCola]

Hi Ann,
I toss 12-12-12 on top of the snow! When it melts it goes in the ground. I read to do it that way a long time ago & tried it & it seems to work since my garden is just gorgeous & people all around ask me how I do it!

I thought watering every 2 or 3 days was what is needed to get about an inch a week. I use a broken oscillator sprinkler that is stuck in one postion or a tall sprinkler that shoots out in a complete circle. Some beds have soaker hoses but not all. I have gauges and they usually say about .4 or .5 after each watering.

So what's everyone's opinion on how frequently to water?

[whip1]

IMO, using fertiliser on top of the snow is just letting the chemicals leach through the soil. The snow melt, and spring rains wash most of it away before the plants get to use it. I wouldn't fertilise anything until it's growing, and able to use it.

With all of the double digging, amending, and mulching, is it possibe the plants have settled too deep? Last year, I planted a new bed and mulched it. Everything settled over the winter, and a few of them struggled because they were too deep. I dug them up, put some soil under them, and replanted and mulched. They appear to be doing better.

[thy]

Hej Cola... I did a long text last day... but think I have saved or deleted it some how

trying to recapture

All of you old ones know my habit with inches... = one inch is similar to a centimerer or maybee even a bit less... I have a small garden
it went fine for years, but them ny Fan Dance turned small last year..
This year it is Christmas pagfeant and a ancient sieboldiana

Water.. I'm cloce to drowning here... not the problem at all and neither was it last year

So what else happened in the garden close to the smaller hostas ?

Their neighbourg hostas increased eceptional good

So here is from my thinking hat ... hostas are hostas worst frinds... Blue Angel roots ate Fan dance... KFM ate a rather big Christmas pageant

I'm so sure i can't wait to dig them up due to my moving house, to see if it is only the roots divining or the entire crown

Pia