Should fallen leaves be left over winter on a flower bed? Ask an Extension expert

Gardening season is starting to wind down, but there’s some things still do, and you may have questions. To ask one, simply go to the OSU Extension website, type it in and include the county where you live. A photo is very helpful.

Q: Last month I planted a brand-new flower bed with bulbs such as daffodils, Siberian squill, fritillary, anemone, crocus, etc. But I also seeded the bed with blue gilia, sea blush self-heal and buttercup. Now the flower bed is entirely covered in maple leaves. Is it best to remove those leaves or allow them to remain in place through the winter?

I’m not worried so much about the bulbs, especially the larger ones like daffodils. Their stems will pop right through or push the leaf away. I was more worried about the seeds. They were simply sown on the surface per recommendations. They’re tiny. Having a leaf on top, whether whole or chopped, seemed like it might be a problem for such delicate new stems to push through. – Multnomah County

A: Leaves are a great soil amendment and help keep the topsoil in place from our heavy rains, so yes, I would leave them over the winter. However, if you leave them whole, they will need to be raked gently off when spring comes, and the first bulbs try to peek through. An alternative is to rake and chop them now, either with a lawn mower or shredder and then put them back as protection for the beds. The smaller pieces will decompose over the winter and give the plants no trouble poking through in the spring. Either way, the leaves are a great benefit to the soil and add nutrients for all the soil organisms to stay healthy.

If the leaves are chopped up, they won’t be a problem, as they will have mostly rotted away come time for seeds to push through. You won’t want to layer them on too thickly, just enough to keep the rain from directly hitting the soil and compacting it. Seeds, like people, have a will to survive and should push right through any remaining leaf litter, since they won’t have washed away by being left uncovered. I hope this helps your decision – Rhonda Frick-Wright, OSU Extension Master Gardener

What to do about aphids on kale

Q: I have several kale plants and these bugs have started to appear. What are they? Will neem oil work? Will a dilute dishwash spray work? – Multnomah County

A: These are aphids. Some home use recommendations include the use of neem oil or soapy detergents. Here’s one. Insecticidal soaps can be effective and should be timed accordingly to prevent damage to beneficial insects. Dislodging aphids with a strong stream of water can be useful in gardens. Crop rotation and removing debris post-season are both important strategies. – Navneet Kaur, OSU Extension entomologist

Trellis systems for apples

Q: In some of the high-density apple orchards I see they have a trellis system to support the apples. Is this a common way to grow apples and a common use for wood posts? – Linn County

A: I’m not an expert on commercial apple orchards, so I cannot say if espalier training is common practice. My first thought is that trees could be pruned this way so that they are easier for people or machines to pick the apples. It is labor-intensive but would be worth the time if harvesting is more efficient. In addition, the ability to see the fruit and space them to reduce pests and disease could be another reason for this orchard design.

Wood posts will rot at the base after a few years but once a tree is established the need for support is lessened, depending upon the style of espalier. And sometimes posts are temporarily used to support branches to keep them from breaking when the fruit is very heavy. Here, here and here are some publications regarding pruning of fruit trees. – Ann Kinkley, OSU Extension Master Gardener

Source: oregonlive.com