Balconies and terraces in September
In September the potted gardens recover after the hottest time of the year: from mid-month onwards the temperatures will start to fall and the rains will become more frequent, favoring vegetative growth and new blooms. It is, together with May, one of the most satisfying months and many compare it to a second spring, but with warmer and more delicate colors. To get the most out of our outdoor spaces we will have to dedicate ourselves on time to cleaning, irrigation and containment of pests and cryptogams
Upon returning from holidays, or simply because of the heat, we can find ourselves with rather bare vases at the base, without flowers and with many yellow leaves. In most cases (especially for geraniums, petunias, verbenas ...) you can intervene by cutting and cleaning quite drastically. We will then follow frequent administration of liquid fertilizer and irrigation: we will see a quick recovery of vegetative growth and bud production.
Similar interventions can be requested by shrubs (roses), climbing or herbaceous re-flowering or prolonged flowering. If we have not done it before (July / August) we can proceed with the pruning of the shrubs that bloom on the old branches. By stimulating growth and spreading we will have, the following year, more abundant buds and a compact growth habit.
Maintenance and propagation
First of all we must continue in the work of eliminating weeds: with the lowering of temperatures and rains they are more frequent and the growth is faster.
Many flowering plants (dahlias, sunflowers, September asters) have large corollas on tall but delicate stems: in order to keep them as long as possible we prepare guardians.
Most summer bulbous plants have reached the end of their cycle (eg gladioli, lilium, hemerocallis). It is not always necessary to extract them from the ground: we proceed every two or three years. We will have to check that they are free from mold and possibly make the division from the side bulbs. We can then place them in a dry and cool place until the following spring.
It is also a good time for propagations: woody or semi-woody cuttings. They will root quickly enough and we will be able to pot them next spring. It is also an excellent time for sowing biennials and perennials: thanks to the mild climate we will have fast germination and good growth.
Irrigation and fertilization
As we have said in this period we can allow ourselves to force the plants a little by administering higher doses of fertilizer. Thanks to the milder temperatures they will not suffer damage and, on the contrary, they will produce new vegetation and blooms. For herbaceous plants and small shrubs we prefer a liquid product, while for larger plants it is good to opt for slow release granules.
Irrigations are also important, but we must always take into account the temperatures, the size of the pot, the substrate and the individual needs of the plant. On returning from vacation we are, for a few days, a little more assiduous, then we return to the usual habits. In general, rather than overdoing it, before returning to irrigate, it is better to wait for the soil to dry in depth.
Works of the month on balconies and terraces in September: Pests and diseases
With the gradual change of season we have a normal rotation also of pests and phytopathologies.
As the temperatures go down and humidity increases, the red spider will become more rare, instead infestations of aphids and cochineal will continue. In less severe cases we can use macerated or pyrethrum, otherwise it is better to use more persistent products (pyrethroids, systemic or, for cochineal, activated white oil). With the fall there is also a return of cryptogams (powdery mildew, scab), prevent them with frequent treatments with covering products, especially after the rains. We also regularly check the leaves: by promptly eliminating those affected we will reduce the spread considerably.