What to do in September in the garden

September marks the end of summer and we are having shorter days and colder months.

The autumn is around the corner and a lot of debris will need to be collected from the garden. This is a great time to buy or build a compost bin.
You can easily build a compost bin by fixing chicken net to four posts forming a square. Then add cardboard in the inside of the box to keep it warm and you can start recycling garden and kitchen waste. It is essential to balance the “greens” and “browns” in the bin to make the best compost. Your plants will appreciate the rich soil that will come from it.

Compost bin

Now the growing season is over, take a notebook with you when you walk around the garden. You can take notes on how some plants have performed during the year, what worked and what didn’t, what needs to be moved, etc.

There are still plants to enjoy at this time of the year and plenty of jobs to do. Deadheading in beds and borders is unlikely to extend flowering, but will make the garden look neat and enhancing plants that are at its best like chrysanthemums and dahlias.

Trees and shrubs in September

The soil is warm and autumn and spring are good times to move evergreen shrubs. Dig around the plant so you can lift as much rootball as you can. If it is a large shrub you may need the help of a friend. Dig a hole big enough to take the root system and plant it at the same level it was originally. Gently firm the soil around the roots so there no air pockets. Stake the plant and water it well.

Planting container grown trees and shrubs can be done all year around but this is one of the best months to do it. The soil is still warm so the roots will get established before the winter come. Another advantage to plant in September is because shortly the rain will come and will no need to water the plant. These two factors will give an important boost in the next spring. Remember to plant at almost the same level it is in the pot, water it well after planting and stake it.

Propagate roses by hardwood cuttings. This is very easy to do. Select a shoot with the thickness of a pencil and cut about 30cm (12in) long immediately below a leaf node. Remove the soft growing tip and let the three sets of top leaves. Dig a trench in the ground, add some grit to the bottom and place the cuttings along it letting the 3 sets of leaves above the soil. Water them and they should be ready to plant in the final position next autumn.

Perennials in September

September is a good month to plant new perennials. The soil is still warn enough so the plants will get established before the winter comes. Visit some garden centers, they should have a good selection of flowering and foliage herbaceous perennials. Perennials are generally cheap, and if you think that you can then lift and divide or taking cuttings, each plant will cost you virtually nothing.

Choose plants wisely, making sure they are appropriate for your garden and intended position. Search for plants with healthy growth and strong roots but not in the point they completely filled the pot in circles. If you not certain about lifting the plant from the pot, just look if there are roots growing through the drainage holes.

Cut down and divide perennials that have finished flowering. Most perennials will not look good in beds and borders as the flowering finishes, so the best thing to do is to cut them down. At the same time, the clumps may be divided and you will get free plants. Lift the plant with a fork or spade and split it in two or more pieces, depending on the size and your plan. Plant them as isolated new specimens.

Collect seeds from perennials as they are mature. Pay close attention to ripen seeds and get them at first signs of maturity, otherwise they will spread away.

Bulbs in September

Plant spring flowering bulbs. This is the best month to plant spring flowering bulbs and to plant bulbs in the grass. Small bulbs can be planted lifting a piece of turf, place the bulbs and put the turf again in place. For bigger bulbs you should use a bulb planter. To give a random and more natural aspect you can throw the bulbs and plant them where they fall.

During September you should also lift gladioli when the leaves start to turn yellow. Leave the old foliage on until it dries completely and then cut it down and store in a dark, dry and fresh place.

Annuals in September

Sow hardy annuals that will flower next year. You can sow them outside or, if your soil is heavy clay, sow the seeds in containers and place them in a cold frame.