You must monitor the seedlings as they grow in their new pots for colour, form, bush size, branching, and disease resistance. Roses with weak, unhealthy or unattractive flowers can be discarded. It will take your new seedlings at least three years before they reach maturity and develop into a big bush. However, the first flower can be seen after one or two years.
Buy bare root or potted roses. Once you've picked out the types of roses you want to plant, decide in what form you want to buy them. Bare roots are the roots of roses that are planted directly into the ground. You can also buy young roses that have already been planted in a small pot, and transplant them to the ground or another pot. Either type may be purchased in a nursery. Rare rose varieties may be found online.
I have successfully taken rose cuttings with both new and old wood. It is important to let the new stems sufficiently mature. The new wood is usually mature enough after the stem has just finished blooming. If you don't let the stem mature enough, then it usually becomes limp and will die before you can get it to root. I take cuttings from new rose stems in the spring right after the first bloom cycle. Then in early to late fall (in Southern California) I prefer to use more mature or old wood. When using old wood in the fall, I will remove the rose cuttings from the Mason jar, baggie, or mister, after only several weeks since it is cool enough then for them to root on their own as long as I water them daily.
When pruning, be judicious. If you prune too hard in autumn, plants can be damaged beyond recovery. Instead, wait until spring, when plants begin to leaf out for the new season. (Roses are often not the earliest plants in the garden to respond to spring’s warming temperatures, so be patient.) Give the plant time to show its leaf buds then prune above that level.
as mentioned when I replied to Mick, the powder with be a fungicide as we’re trying to help prevent dampening off – although careful watering is always the best solution to this problem. The hydrogen peroxide mentioned in the blog will be the same as the hair bleach and is just an extra precaution taken by the author to sterilise her seeds. Using normal bleach in tiny quantities is usual practice in preventing harmful bacteria in seed processes, especially if they are prone to disease in the first place.
Pests and diseases: Prevention is the best way to avoid pest and disease problems. Start with disease-resistant varieties, keep plants in healthy condition (well fertilized and well watered), maintain good air circulation, keep foliage dry, and remove any diseased foliage or spent flowers. For Japanese beetle grubs, use beneficial nematodes or Milky Spore (Bacillus popilliae). Rose Rx is effective against scale, spidermites and aphids. For more information, see the Pest and Disease Finder.
Taking rose cuttings can lead to a new crop of beautiful, successful roses. Like many other plants, it's important to choose a sunny spot for your rose cuttings that has moist soil. Cutting strong, healthy stems right above a set of leaves makes for great growing conditions, and dipping your cutting in a rooting hormone will help the roots take faster. By keeping your rose cuttings well hydrated, you'll have strong roots in no time.
Please keep in mind that many rose bushes are grafted rose bushes. This means that the bottom part is a hardier rootstock that will withstand cold and heat better than the top and more desired part of the rose bush. Starting a rose bush from cuttings places the new rose bush on its own roots, so it may not be as hardy in cold climates or in extreme heat conditions climates. Being on its own root system can cause the new rose bush to be far less hardy than its mother rose bush.
Black Spot: Rose plant leaves with black spots that eventually turn yellow have black spot. This is often caused by water splashing on leaves, especially in rainy weather. Leaves may require a protective fungicide coating, which would start in the summer before leaf spots started until first frost. Thoroughly clean up debris in the fall, and prune out all diseased canes.