Rose Cultivation Tips
Please note these tips are gained from my own experience and conditions (USDA8/9) only and cannot be applicable in all situations, and I take no responsibility for any application of these tips.
I live in an area which is made up of very hard alluvial clay soil and rocks, approximately a 50:50 mix. This makes it very hard to plant roses in, so I took the easy way out and built raised gardens. This ensures I can plant the roses in the optimum conditions and they have the good drainage which is so necessary for them.
Roses need lots of sun, all day if possible, many will not flower well or at all in shade. I have planted mine in North and West facing gardens to ensure that each garden gets at least half a days sun minimum. My roses have been planted a bit closer than recommended (1 M between each main stem) but it was a choice I made to fit more in. In one garden I planted them in a zig zag pattern to fit more in compared to a straight line in the other gardens. I like the zig zag style, it is less cluttered and easier to work around the bushes.
We did install an irrigation system with drippers for the roses, but our pressure is so low that it doesn't work very well for us, we would have to leave the system on all day for it to work, and water restrictions this summer have limited irrigation use severely. I water a couple of times a week, giving the roses a big drink each time. In a couple of the older roses, I actually poke the hose down into the roots about a foot and run it there for a while. It is the first time I have tried it and I think it works quite well, they are certainly the best looking roses in my garden at the moment.
I planted my roses in good soil, with lots of mushroom compost dug in to the top foot or so, and mulch them with the same compost. I like mushroom compost and use it everywhere in the garden, but it does make a good mulch, and I saw its worth in the drought this year.
I give my roses a good start by giving them good soil to start with. I feed about 3-4 times a year with Floravite, I have found it very good. Many people in NZ swear by Nitrophoska and I might try it next year. I also go round a few times with Thrive diluted in water as well. I might try Potash for colour next year but intend to get a soil test done at some stage first. Overfeeding can be as detrimental as the reverse.
I do my big prune around late July, depends a bit on the weather. We get frosts here and they can go on through spring, so lots of finger crossing goes on about then. I also do a good summer prune around December to clean up the roses, and have found that gives good growth later on, and I tidy up prune a couple of months later. I tend to prune hard one year and easier the other, I am still new at this and learning what works for each type of rose. I have learnt that roses are very forgiving and have never killed one yet from over pruning. I am an angle cutter FWIW.
I am lucky to live in one of the best rose growing areas in the world, we have hot dry summers and cold dry frosty winters, so diseases are few. Black spot on the susceptible roses but not a lot, and sometimes powdery mildew. I only spray with baking powder spray for the mildew, I have given up the fight with BS and just try to keep hygiene as good as possible to help that. I hose off the aphids and that is about all.
I go around dead heading regularly, this helps keep disease under control and encourages more flowers from the rose bush. I strip leaves from autumn onwards, once they start looking a bit had it. This helps keep the beds clear of old leaves. I fixup prune where necessary and tidy up with my bigger prunes during the year.
Regular and sufficient watering is the best thing for your roses, if you neglect that the bush has little energy to defend itself from other problems. If you grow roses in pots it is even more vital, I have watered some pots 3 times a day as it was so hot here. I found burying roses still in the polybags in a spare spot in the ground beneficial, it helps retain moisture, and they don't get blown all over the place by the wind.
Questions or Comments? Email me!