Thomas has written in concerned that he may have killed his potted knockout roses. Here’s his story:
I purchased knockout roses about two weeks ago. I haven’t planted them yet, they are sitting on my patio (1st week shade/ 2nd week full sun). I’m not sure what happened but they looked very healthy when I purchased them. They were starting to bud during first week but over the weekend I noticed that the buds are dying and the leaves are also withered and dying.
I was watering them once a week and it also rained a few days last week. I have since removed the dead leaves, etc. I also checked the soil and I noticed that is was semi-dry. Since I noticed the withering/dead leaves, for the past two days I’ve been watering them every other day but I’m afraid of overwatering.
After watering, I check the soil and its semi-moist but the next day it feels somewhat dry again. Maybe I’m watering too little? Is there anything I can do to help them recover? Thanks!
it sounds like the soil in the pots has dried out at some stage in that first week. The soil in pots dries out very quickly, and any rose in a pot needs watering more than once a week (even during winter I water my potted knockout roses, which are in full sun, about every 3-4 days)
You’ve got the right idea now, with checking the soil to see if it does need a water, so this predicament shouldn’t happen in the future.
Also taking your potted knock out roses from sitting in shade for a week into full sun straight away the next week wouldn’t have done them any good either….it would have added more stress to the plants on top of their lack of water.
With any plant that’s been in the shade for a week or more, you need to climatise it slowly back into full sun by putting it in a semi-shaded spot for a few days then a spot that gets a bit more sun, then finally into full sun.
Anyhow let’s see if we can’t save your potted knockout roses. Watering every second day sounds good; but if the soil feels somewhat dry the next day, it may need watering again then. Some potting mixes are very light and don’t retain water as well as others depending on the ratio of ingredients used in the mix.
The only way to know for sure is to just stick your finger down a couple of inches into the soil and if it feels like it needs watering, water it. Pots usually have plenty of drainage holes at the base, so the pots aren’t going to retain a lot of water anyway.
If anything is going to save them, good old liquid seaweed will do the trick. If there’s any semblence of a fine-haired feeder root left on the main roots after the plant has dried out, liquid seaweed, with its abundance of minerals and enzymes will help intitiate more of them.
I’ve written a good article here about the wonderful benefits of using liquid seaweed.
You don’t want to over do it though. Just make up a solution of liquid seaweed and water at half of the recommended strength. (eg if it’s 1 capful liquid seaweed to 1 gallon water, make it 1/2 a capful to a gallon of water).
Be sure to give the knockout roses a good watering first, then apply the 1/2 strength liquid seaweed solution. Use any remaining mix on your other plants as you have to make up a fresh lot every time.
Do this every 4 days (after a good watering) for 3 weeks, then once a week. I use liquid seaweed (in addition to regular fertlizing) once a week on my potted knockouts and they thrive.
Do not use any fertilizer on them at this stage either; just the liquid seaweed.
Do not plant your potted knockout roses into the ground until they have well and truly recovered and have fully leafed out. Good luck Thomas and let me know how you go with them.