You can kill a plant by spraying it with oil....
I don't have a deep problem, so I don't know what works best.
Linda C

I do not use oil in my mix and I made the mistake of putting Wilt Pruf in it once thinking it would act as a sticker/spreader. All my blues had spots where the glaucous coating was removed byt he Wilt Pruf. If I do not use anything as a sticker spreader and reapply often it work great without any unpleasant side effects.

Alexa

Hi Linda~
There is only a very tiny percentage of oil in the mix, and I've seen the recipes printed several times. Don't think it will kill, just ruin the looks.

Alexa~
Thanks. Your experience confirms what I have been suspicious of. The deer are bad around here, numerous and very bold. I spray often, and have been very worried that I am doing harm. It isn't as obvious on the blue variegated plants because there is less blue than the other colors on most of mine. But the big blues are showing ill effects. The gorgeous new Silver Bay that I've had in a nice ceramic pot until recently is no longer pristine. I decided to put it in the ground, and accidentally sprayed it in the dark. Bummer. The Fragrant Blues will flush again, so they will look better soon, but the others blues won't look good again until next year.

Still a hosta newbie after 3 years. Live and learn.

~Bunnycat

I am a produce manager n I have lots of peps who come n asking for my hottest peppers . they boil em n spray there flowers wit it not sure wut all they mix but hot peppers r cheap at only bout 2 bucks a pound.

I add both cayenne powder and whatever cheap hot sauce I can find as part of the mix. If it burns my hands if I spill while refilling, I know I mixed a potent batch.
:o)

While I was away, DH left the opening to the deer net for a few hours while watering. The deer ate most of the hosta flowers and some of the daylily flowers. I hadn't sprayed the flowers because I didn't want to upset my bees.

A few days ago, after some heavy rain, I didn't spray again IMMEDIATELY. The deer came at night and rammed the net fence, ate most of the rest of the hosta flowers and most of the remaining daylily flowers. Argh! What good are daylilies without flowers? At least the deer only nibbled leaves from 2 Honeybells. I must have missed spraying them. I am so happy that SO FAR my hosta leaves are largely intact.

But, I could always have more 4-footed visitors tonight, or the next night, or the next.....

~Bunnycat

Here's a homemade recipe I just read about today.
It came in an advertisement for one of Jerry Baker's Gardening Secrets books.

1/2 cup Murphy's Oil Soap
1/2 cup lemon scented dishwashing liquid
1/2 cup castor oil
1/2 cup lemon scented ammonia
1/2 cup extra hot pepper sauce
1/2 cup of urine, Yes Urine!

Mix these ingredients together in a 20 gallon hose end sprayer, then apply to the point of run-off to any flowers or shrubs that need protecting.

Said to repel deer, rabbits and any other varmints making mincemeat out of your flower beds.

Janet

I had the same experience with an anti-rabbit spray that included oil - it dissolved the bloom on my blue hostas in hideous spots & splotches and that's how these leaves stayed all summer. I hated it. Of course, this didn't hurt the plants, just destroyed their beauty for the season. I was upset that the recipe didn't include a warning about leaf discolouration, after all what's a garden if not for aesthetic enjoyment?!

If I ever spray plants again, I'll be sure to avoid any with th bloom (including gold ones with bloom like Zounds, and green ones like Black Hills), but stick only to the shiny leaved ones. That sort of selectiveness makes the exercise almost not worth the trouble for me.

An alternative is to coat a quantity of coarse sand with the "spray" recipe, and throw that on the ground around the plants. That's the basis for a preparation called "critter ridder" - the peppery smell repels animals from coming in. People say it works very well, so I may try that yet.

Digs.

I don't know if this works or not, and it may be impractical for most people, but a hosta grower in Northern MN, which has lots of deer, told me he put pallets around the peremiter of his property as deer won't walk across pallets. Thought I'd add it for what it's worth!