September Tips for the Garden

September is here and fall is right around the corner. It almost time to get the garden ready for winter – but not yet! September to me was a time of birthday parties, picnics before school, and the last summer vacation.

What needs done in September first?

• Remove spent and over-grown annuals from the landscape beds and prep them for autumn color
• I like to remove all the summer annuals and replace them with pansies, stock, Swiss chard, mums, dusty miller, ornamental cabbage and kale, and pumpkins & gourds
• Remember to keep picking your tomatoes, cucumbers, peppers, eggplant, watermelons, beans, and anything else that is ripening in the veggie patch. Get these packed away for winter or eaten as fast as possible before more is picked

Is there any prepping I can do for next year?

• If you are wanting to expand, now is a good time to get new garden spaces set up for next season
• Design and put in new raised beds or Hugelkulture beds
• Mulch pathways with sawdust, pine straw, or wood chips

Can I plant spring flowering bulbs now?

Yes, if you have pre-ordered your bulbs they should have arrived by now and are waiting to be planted. Or you can shop at local garden centers (Grimm’s Gardens) for your bulbs.

• If you know where you are planting them, go ahead and get it done before autumn really sets in
• Be sure to mulch any new beds of bulbs you put in
• Plant crocuses and snowdrops in the lawn where they can spread and multiply

Is it a good time to divide my perennials?

September is one of the best times to divide a large number of perennials. While spring is also excellent for perennial division, I prefer to do it in autumn, before the garden sleeps. This way, I am less likely to encounter wet soils and tearing up the garden in fall does not detract from the beauty as it does in spring.

• Divide Siberian, dwarf, and German bearded irises now. One clump of Siberian iris can be divided into as many as 15 divisions, so share with friends!
• Older clumps of peonies can be dug up and divided now, just remember it takes 3 years for divided clumps to get back to regular flowering
• Hostas grow quickly and can be divided now and spread through the shade garden
• Daylilies can be divided anytime of the year without harm, but fall is easier (after the foliage is cut back in August)
• Other plants for division in September include: goldenrod, asters, willowleaf sunflower, false sunflower, Rudbeckia laciniata, Red Hot Poker, Liatris aspera and spicata, Allium ‘Millenium’ and ‘Summer Beauty’, and bleeding heart

When should I start planting trees for next year?

While you should have planted trees 20 years ago, now is another great time to plant. Most trees are already dormant by September first, responding to environmental and day-length changes in the climate. Plant trees from September until the ground freezes in November or December.

This is also when many nurseries have year-end sales or tree sales to move extra inventory out. This does not mean that the plants on sale will not survive the winter, the nursery just does not want to have them on hand. So plant them!