Gardening Monthly Calendar- September
Sep 4th 2017 ⋮ in Advice

What to do your garden this month: September

Grimsby Garden Centre’s guide of what you should be doing in your garden in September.

September is usually a slightly cooler, windier month than the summer months we’ve just had. You may find yourself with less to do in your garden at this time of year, unless you grow fruit and vegetable of course, in which case you’ll be reaping the rewards of your hard work in the garden this summer and harvesting your fruits and vegetables.

Now is also the time to collect seeds from your current healthy plants to boost next year’s colour in your garden, also begin planting your spring bulbs ready for next year.

September is usually our last chance to squeeze any warmth and sunshine left out of summer, so make the most of any fine days you get to spend in your garden!


Colin, horticultural manager at Grimsby Garden Centre: “September is the time you should be thinking about prepping your garden ready for the cold weather. You should be thinking about planting spring-flowering bulbs to brighten up your garden in the spring- now in stock along with bulb compost in the garden centre. You also should be thinking about treating your lawn with a feed such as Evergreen Autumn Feed, getting it ready for winter. If you have any decking make sure to treat it now.”


Pick your autumn fruiting Raspberries:

  • Autumn fruiting raspberries should grow fruit from late summer months all the way through, until it begins to frost.
  • Autumn fruiting raspberries are ‘primocanes’ so once you’ve reaped the last of the fruit in late autumn, you should cut down the canes to allow the plant to grow fresh canes throughout spring.
  • You may also want to save back a few ripened raspberries to try to collect the seeds from, pushing them through fine sieve, hard enough to crush the fruit but not the seeds, rinse off excess fruit and dry the seeds.


Collecting Seeds:

Many types of plants grow seeds that are suitable to be collected and saved including types of trees, perennials, biennials, annuals, shrubs, alpines, bulbous plants, herbs, vegetables and ornamental grasses.

When should you collect seeds from your plants?

  • Usually, the seed is set around two months after the plant has flowered.
  • Seed heads can become ripe quite quickly, so you must keep an eye on your plants to collect the seeds before they are dispersed.
  • Birds will have their eyes on your berries so make sure you get to them before the birds do!
  • Any plants which you are collecting seeds from must appear healthy, to ensure that the seedlings are also healthy.

How to collect seeds from your plants?

  • When the seed heads are ripe they will change to a dark brownish, reddish colour, this will happen just before they open and shed their seeds. Collect the seeds on a dry day.
  • Lay out the seed heads in a dry spot to allow them to dry out, if the seed head do not open easily when they are dry, gently crush them until the seeds pop out.
  • Seeds from fruits can be collected by crushing the fruits in a very fine sieve, and rinsing away the pulp from the fruit. Be tough enough to squish the fruit but gentle enough to not crush the seeds.
  • Give fruit seeds plenty of time to dry off after rinsing them.
  • Clean off any bits that may cause the seed to mould and attract pests.

 The best way to store your seeds once collected?

Some seeds may lose capability when stored so are best to be sown straight away. However, most seeds are best waiting to sow until a better time of year such as spring comes along, so will need to be kept safe until that time.

  • Humidity can be damaging to seeds, so keep them in labelled paper packets in airtight containers, with a product such as silica gel to remove any excess moisture from the air.
  • Store in a refrigerator to keep cool, many seeds will last a long time if stored properly.

Dig up your last few potatoes:

Slugs can damage your potatoes so make sure you get to them before the slugs do!

  • All of your potatoes should be collected before the middle of October to avoid damage from the great British weather.
  • Only lift them on a dry day, and give your potatoes a few hours to dry on the soil before you store them.
  • Store in a frost-proof area, avoiding storing in any plastic or paper materials which may allow them to rot.

Cover your pond before the autumn leaves get in:

  • Remove any dead or dying leaves, flowers around the area of the pond to avoid rotting leaves and debris from damaging the pond life.
  • Use a netting cover to avoid any leaves falling into the pond.

Begin to reduce how often you water any plants as the temperature starts to decrease. As the weather gets colder, allow the compost of your houseplants to almost fully dry out before you water them, unless they are flowering.


Use bird proof netting to cover any leafy vegetable plants.


Now’s the time to be killing off any unwanted tree stumps- in the garden centre we recommend ‘Doff Tree Stump & Tough Weed Killer’.


Lawn Care

  • You may want to start thinking about increasing the blade height on your lawn mower, depending on the weather.
  • Begin to treat your lawn with autumn food- Grimsby Garden Centre stock Evergreen Autumn Lawn Care Feed.


During September you should now be getting in any spring flowering bulbs from the garden centre, along with bulb compost:

  • Spring flowering bulbs such as hyacinths and daffodils should have been planted by the end of September.
  • Bulbs for other plants such as Tulips can wait until around November time.
  • Summer-flowering plants such as lilies and alliums.
  • Plant hardy bulbs like to be planted in a warm, sunny spot with good drainage, plant them in larger groups to make for a better display.

During September begin thinking about buying winter bedding, now in stock in the garden centre.

If you have any decking in your garden, make sure you treat it in September, before the winter weather gets fully underway.