What brand of fertilizers do you use for your irises? I need to give my irises (older ones anyway) a little feed before the fall here soon. I know I have read that Epsom salts help when its about time to produce flowers. Any help is appreciated.

Good question. I have heard you fertilize them one month after bloom and in the spring before bloom but do not know what to do now.

I use 10-10-10 you just sprinkle it around and done!

I have one row I am trying out rabbit manure. But that's a test plot so we will see.

I use 6-20-10 and get a 50lb bag of it at Horizons for about $27. I also use some alfalfa pellets, but make sure you buy some that have no additives, such as salt. I bought the pellets at a animal feed store nearby and I don't recall the brand name.

I done the same as Jen does with triple 10. What ever brand I can get. That reminds me I should do this. Way to many things going on.

I have a big bag of alfalfa pellets that I bought at a feed store and used one season but I think they may cause mold when we have lots of rain. Does anyone know if that is the case? Also what about Epson salts?

Cory, I think that's all of us now a days I think. Just a lot going on.

Jane, I have heard some use Epson (Epsom) salts during the growing season, but not have heard about the alfalfa pellets.

I don't use fertilizers high in nitrogen. I think it encourages rot. everything you add, such as alfalfa pellets, has a little, or a lot, of fertilizer in it. if you are using a multitude of treatments then you may not need regular fertilizer. Research all the home remedies and additives, get a soil pH test and then decide what you need to feed your irises.

In our area it's not a good idea to fertilize in the fall. The new growth isn't strong/hardened off enough to withstand the winter and it can cause death and rot. I only fertilize in the spring with a balanced fertilizer. The super phosphate fertilizers aren't legal here any more, as it leaches into the water supply and causes problems.

Maybe at first do no harm is the rule. Sometimes a little may be too much if you are doing all kinds of things at once.

I'm think as long as you make sure you test soil yearly you can pretty much do what ever you want to try to see if it works for your soil or not. I test my soil 2 times a year. Never had a problem.m. Now I also drop lime and gypsum in late fall so it's all fresh come spring.

I agree with Tom, ....I wouldn't fertilize them now.........besides causing a "growth spurt" at the wrong time, most of you fertilizer $ will just leach away ,over the winter. The best time , IMHO, is as soon as new growth stars ,in the spring. A *small* side dressing, about 2 weeks after bloom is over will also do you some good. If you are growing Re's, they can stand a bigger "dose" at that 'post spring bloom" time.

Jen - (pardon to all of you who hear me say this often) if you have Japanese or Siberian iris do NOT use lime on them as it is poisonous to them. They like 10-10-10 and need to be fertilized again in the fall because their requirement for more water leeches the nutrients out of the soil quicker.

Lestv said:Jen - (pardon to all of you who hear me say this often) if you have Japanese or Siberian iris do NOT use lime on them as it is poisonous to them. They like 10-10-10 and need to be fertilized again in the fall because their requirement for more water leeches the nutrients out of the soil quicker.

Thanks Leslie, I have heard that a time or too. I never put any around my Japanese iris. Now my siberians have had a dusting here and there and they still are multiplying like crazy!

The ones who use a fertilizer, do you use granules or a liquid?

Granules.

A bargain store had some Pennington Bulb & Bloom food. I sprinkled some around a while back. It is 10-20-10. I dunno how it will work. We will see next year.

I top dressed some new plantings with well broken down kitchen scrap compost.

I wouldn't let the new compost touch the rhizomes.

As for the fertilizer (granules), I only lightly apply it in Spring and after the majority of blooming is done. I work the fertilizer into the soil with a three prong cultivator. In Spring, I will also work some alfalfa pellets into the soil at the same time as the fert. When I plant, I work alfalfa pellets (or bone meal) and some fertilizer into the hole and mix it in.

If I don't work the alfalfa into the soil, the jackrabbits and bush bunnies will have a field day.

Rob,
What is Horizons? I can only find triple 10 or triple 13... Best I can do on the low Nitrogen side is Bone Meal..

http://www.horizononline.com/

If there isn't a Horizons around you, look for a product called Super Bloom. I've never used it on irises, but it has a low nitrogen and high phosphorus rating.