Keep your trowel active in October – there’s plenty to do outside on cooler, sunny October days. Include indoor garden projects too – I’ve already purchased yellow narcissus for indoor forcing – woohoo … the yellow ones smell nice!
- Plant in areas where summer vegetables and ornamental annuals grew – anywhere where there’s bare soil.
- For fall cover crops look for winter rye, oats, Austrian winter pea or hairy vetch seeds in garden centers or online. Plant by mid-October when the ground is still warm so they sprout, grow and provide coverage all winter.
- Follow package instructions for seeding depth and area coverage. They will need water to get established, but generally no care after that until next year.
- In late winter, or when the soil isn’t too wet, cut down the growth low to the ground (it may not be very tall), then turn it over, giving it a least two months to break down before planting the first crops or annuals.
In the landscape
- Early in the month there is still time to divide and replant or share overcrowded perennials. The general rule is to divide early spring and summer blooming perennials in the fall, while dividing late summer bloomers in the spring. Cut back top foliage before dividing.
- One of my favorite, easy, go to documents on what to divide and when is from Garden Gate Magazine. Click here. It doesn’t include each and every perennial we grow in the mountain west, but a good reference none-the-less.
- Continue planting spring-blooming bulbs through November as long as the ground is not frozen. Water bulbs during dry weather all fall and winter.
- Bring herbs such as basil, chives, rosemary and oregano indoors and grow near a sunny window. Carefully dig up a portion of the plant with roots and place in a sterilized container using new potting soil. If gnats or insects have hitchhiked onto the leaves or parts of the soil, treat with insecticidal soap. In some cases outdoor dug herbs may not produce well from lower winter lighting, so supplement with grow lights as needed.
- If you’re decorating outdoor containers for the fall and winter with twigs, pinecones and other winter do-dads, be sure to clear out spent foliage and potting soil to make room for your creation. Do this well before the weather turns cold so the potting soil doesn’t freeze.
- Perennial weeds put on deep growth in the fall to get them through the winter, so get a jump on next year’s weeds and remove them now. Hand dig or spot treat.
- No needs to toss leaves in the garbage, some municipalities have collection or drop off sites through early December. Check with your local county.
- Denver leaf drop and post Halloween pumpkin compost information at 3-1-1 or click here.
Trees and Shrubs
- We’ve been dry most of the summer and into fall. How dry are your landscape trees and shrubs? Are they ready for winter?
- Plant roots need to be moist going into cold weather prior to the ground freezing. Dry conditions can lead to root and branch death, and less foliage next year, or no foliage.
- Trees (both deciduous and evergreen) require moisture to a depth of twelve inches through the growing season. Sprinklers and drip lines may not have provided enough water. It may take time to re-hydrate dry trees and shrubs, so focus on it now while temperatures are mild. Water will soak down much easier now than when soil is cold or frozen.
- Check the soil surrounding tree and shrub roots. The easiest way is to poke a long screwdriver into the ground where tree roots are growing (mature tree roots can extend two to four times wider than the height of the tree). If it goes in easily the ground is moist. If you need to push the screwdriver down, the area needs water.
- Get the landscape well hydrated before sprinkler turn off or supplement dry areas by using hoses and sprinklers.
- A fall aeration followed by fertilization is very beneficial to the lawn. The fertilizer moves into the holes left from the plugs and gets right to the root system. Water the lawn a day or two before aerating so deep plugs are pulled.
- Areas along the Front Range affected by Japanese beetles can apply products in the fall to kill larvae that live in the soil below turf all winter. Adult beetles emerge next summer, so ridding larvae in the fall may reduce numbers and or turf damage. I wrote about this on a recent blog, click here.
- Schedule the automatic sprinkler shut off for the season.
- Take stem cuttings from geraniums for new plants next year. Root 4-6 inch cuttings in fresh potting soil and keep in bright light. Also take cuttings from coleus, fibrous begonias, sweet potato vine and place in water until rooted, then pot up and grow as houseplants near a sunny window.
- Plant amaryllis bulbs indoors in October for December bloom.
- It’s time to cue Christmas cactus to bloom from Thanksgiving to Christmas with cooler temperatures (60 degree nights) and nine hours of sunlight daily for approximately six weeks. Reduce watering when the flower buds form, then weekly as the buds swells. Flower color deepens when the plant is allowed to dry out between watering (too dry and the flowers will drop).