My 'Knock Out' roses are putting on new growth very slowly and the new growth is light green. I didn't fertilize them in early spring. They are planted in fiberglass whiskey barrels. I bought rose fertilizer supposedly formulated specifically for 'Knock Outs" and supposedly guaranteed not to burn them. I also have a small 'Grandma's Yellow' rose that was planted into a whiskey barrel about 3 weeks ago. It was a little sickly looking to begin with light green leaves. It is putting on new growth; however, the leaves are still not greening up. All of these roses appear to need fertilized. I'm hesitant to fertilize anything in this heat. Should I dare fertilize them now? Should I apply the fertilizer at half strength? If I do, should I apply the fertilizer in the morning or the evening? I'm not a rose expert so any advice will be appreciated.
Fertilizer roses in this heat?
I am not an expert .. I have been growing Knock Out roses for more than 6 years now.
I selected them before they became really popular at Home Depot and Lowe's and on every body else yard ...
the reason why I choosed them is because they belong to the "Earthkind" rose group (http://aggie-horticulture.tamu.edu/earthkind/roses/), which are roses selected to be no fuss, no diseases, no trimming , no problems, no much water needed ... so I don't even look at them and they have performed amazing for me all this years.
I have never fertilized them ... right now they are jus sitting there ... blooming, but they are getting ready for the september show !! that's when they will came alive again for me.
They are in full sun and they are taking the heat all day long.
I just wish for more rain ... actually ; for "some" rain ...
Good luck
I haven't ever fertilized mine before. They are doing very well in the heat and have no fungus or any other problems. The new leaves are a "puny" color; however, it just may be the heat. Being in containers, I thought that they may need a bit of fertilizer this year.
I wish we could at least have a shower that would water the grass, trees and plants at least a little bit. 8 months here without a good rain is hard on everything. We received some moisture in March, but it barely washed the dust from the cars. The city water has an excessive amount of chlorine as well as fluoride. The chlorine is so strong at times, it discolors the plant leaves. My neighbor who has a swimming pool tested the chlorine level in our water and one time it was 5 times the amount required for a swimming pool. Not good for humans, animals nor plants.
As long as the roses are getting water on a regular basis, you can fertilize your roses. Whether in the ground or in pots, they will eventually use they nutrients available. As with any living thing, they need food. You could cover the surface of the potting mix with some compost. It would serve a dual purpose: provide nutrients and help keep the soil cooler.
Some plants will go into summer dormancy because of the heat. I've noticed that they just stop growing regardless of the amount of water or fertilizer we provide, but otherwise they look healthy.
Chlorine will dissipate after a while when exposed to air. Do you have a large container or open tank that you could put the water into — one with a faucet attached down low so you could water directly from it using the pressure of the water in the column?
So good to hear from you. I have the rose container soil covered with mulch; however, it does not decompose as quickly as compost. These roses do slow down growth in this kind of heat. They are producing blooms which are much smaller than their spring and fall blooms. Thanks for the help. I think I will give them the rose fertilizer; however, only about half the recommended amount and see what happens. If the new leaves do not green up, I will give them a little more fertilizer in 2 weeks. The reason that I have concerns is because I have fertilized before in heat like this where extra water is needed and some plants have experienced fertilizer burn.
No, I don't have any type of large container or tank as you describe. I have been filling 5 gallon paint buckets and letting the water "sit a spell" before watering my hanging baskets and some other containered plants with the water.
Have you gotten any rain lately?
We got 2-1/2" in May and maybe a total of 1/2" since then. Fortunately, a friend of ours talked me into downsizing our herd in early February. I kept only the registered Angus who made up about 1/3 of the herd. We won't be able to do anything with our hay pasture. So I've given the herd access to it. That will keep them in grass & stubble for about a month. If we don't get rain by then, I'll have to start feeding them hay. I'm already supplementing the nutrient poor grass with grain. It's been a bad year for ranchers and farmers.
bettydee,
the cost of grain and hay has soared. Sure hope that you receive some rain soon. I knew you had cattle and was hoping that you didn't have to buy supplemental food for them.
htop, I'm an Epsom Salt believer for roses. Among my other roses I have 5 knockout. Just a couple of tablespoons scattered at the base and watered in seems to give them a boost. The year of 2011 will certainly be a test of survival of the fittest. We had record breaking low temps in February and now we are breaking records for heat. As you say, "city" water helps very little but sure does wreck the pocketbook.
LouC, thanks for reminding me about using epsom salt. I had forgotten all about it! Usually, I use it quite a bit especially on my angel trumpets. Gotta go buy some! :o)