Mini Growing Tips
Do NOT expose new minis to direct sunlight right away as you may burn the foliage. Keep in the shade for at least a week and then gradually give them 2 to 3 hours of sun a day, for a week to 10 days. After this, you can then safely put them in full sun.
When you buy a new mini in a 3 to 4 inch pot, do not plant it into the ground right away!!
If those small pots are full of new roots, I cut about a 1/4 inch off the bottom of the root ball with a steak knife. This way new fine hair roots will develop really fast. I first transplant mine into one gallon pots. After 3 to 4 months the one gallon pot may have roots right down to the bottom. If roots go around in circles it’s time to transplant into 2 gallon pots. Again, I cut about 1/2 inch off the bottom with a large steak knife. From a 1 gallon pot, one could plant them straight into the ground, but I prefer to leave them in the 2 gallon pots for the first season.
Years ago I did some experiments with my own minis and those which I grew initially in pots were 2 to 3 times larger, after one season, than those which were planted into the ground immediately. Up north the ground never warms up properly until late May compared to the pots, where the soil warms up fast with just a few hours of sun per day. In the southern (or hot) US states, it should be okay to plant right into the ground immediately after purchase.
Do NOT use chemical fertilizer for potted roses!!
My friend Tony and I have both killed a number of minis, growing in one or two gallon pots, using the fertilizer we use in the rose beds. Too much nitrogen, concentrated because of the small pots, will damage or kill the roots and the plants may die.
Use slow release Osmocote or even better, use the organic mix which Tony Denton and I have been making for ourselves and for members of the Vancouver Rose Society. You can not over fertilize (kill the roots) with our organic mix. Tony and I have been using this organic mix for the last 6 to 7 years with outstanding results. The foliage, health and vigour of our orgaanically fertilized minis in pots is exceptional as our rose show results prove!
Water soluble fertilizer can also be used. If it calls for a teaspoon for 4 litres or 1 gall. of water use a level spoon, but never a heaped one. As this is also a chemical, rather use a bit less since too much of this fertilizer may also damage the roots although it may not kill the plant. Again I am speaking of my own experience.
Never lets your pots dry out and note that they have to be watered more often than roses that are planted in the ground.