Gardens writer

Fall is a great time to transplant. One of the reasons is because you don't have to water as much to get plants established. Once the rains start in earnest, you're done!

Another reason fall is good is that the soil is still warm from summer and will retain heat for quite a while - which helps promote root establishment.

"As a rule of thumb, you can continue to transplant until soil temperature gets below 45 degrees," says Marti Olsen-Haworth, a Linn County Master Gardener.

But the main reason Olsen-Haworth likes to transplant in the fall is because - that is when almost everything is on sale at the nurseries.

Taking root

Olsen-Haworth has lived and gardened north of Millersburg for the past 18 years alongside her husband Kevin Haworth. She has been a Master Gardener since 2000 and boasts more than 400 varieties and some 1,000 plants she's added to her garden over the years. She's also a freelance garden writer in her spare time for Home and Garden Journal and Seasons magazine.

An avid rosarian, Olsen-Haworth currently has 154 rose bushes. She showed how to transplant her latest, another David Austen (L.D. Braithwaite).

She also recently transplanted Kousa dogwood, Styrax japonica (Japanese snowbell) and coral bark Japanese maple (Sango-kaku) - all excellent trees for the landscape. The first two were chosen for their spring blooms and fall fruit (seed pods), the latter for its great leaf color and stem color after the leaves have fallen off.

"The colder it gets the redder the bark!" Olsen-Haworth says.

However, her new love taking root is Japanese forest grass - the 2009 perennial of the year! It gives great light to an otherwise dark spot in the garden.

Happy feet

Anytime of year you transplant - care of the root system should be foremost on your mind. Death shortly after transplanting is usually attributed to root damage.

One of the keys to "happy feet" is to adequately prepare a planting hole for those roots to grow into.

"Dig your hole twice as big as the root ball and plant at the same height it was in the pot," Olsen-Haworth says. Mounding the soil a bit allows for some inevitable settling, she adds.

Never plant too deep, unless your plants love moisture. (Small berms around plantings in spring and summer to hold water - is an exception to that rule.) Otherwise, standing water around roots for any prolonged period will suffocate them.

Clay soil doesn't drain well, so Olsen-Haworth recommends "score the hole" (more important for tree or shrub than for annuals) by making slits in the side and bottom of hole with the tip of the shovel. This gives roots a place to grow into.

Fluff up the bottom of the hole for the same reason and make sure any granular fertilizer, when deemed necessary, is stirred in so it has no direct contact with the sensitive roots or they will burn.

When you transplant, use this opportunity to amend the soil with compost and use a root stimulator. Olsen-Haworth recommends watered-down liquid fertilizer at half-strength - and low in nitrogen for fall application.

"You want to encourage your plants to go dormant, yet have a good root system," she says.

Teasing your plants

The plants you find on sale this time of year typically have been in their pot for some time. Any found to be root bound should be "teased" with your fingers or scored (slicing about four times with a sharp knife) to loosen and spread the roots out so they will grow as nature intended. If you just plunk them in the ground as they come out of the pot the roots may girdle the plant and stunt future growth.

Trimming dead or unsightly limbs from trees or shrubs and cutting back top growth on perennials (by half) when you move them allows the plant to focus growth on their roots - not on blooms. It also reduces the plants need for water. Plants won't be as stressed and go into as much shock that way.

Another good reason fall is a great time to transplant is because many perennials are done for the summer and can be cut back now. This makes it a lot easier to see what you are digging up and dividing!

Once your plants have been moved - water them thoroughly.

"Use an inch of water a week - until the rains start," Olsen-Haworth says.

Then mulch. Mulch will help hold in moisture and keep the soil warm promoting new roots well into fall. It also provides a layer of protection over winter. Leaves are plentiful this time of year and free! As leaf mold decomposes into some great soil it attracts worms which help aerate the soil - a win, win situation.

Overplanting

Fall is also a great time to plant bulbs. Olsen-Haworth loves to mix her oriental lilies - Easter, trumpet, star gazer, Asiatic - which she divides and replants each fall for color throughout the seasons.

"They don't do as well if you don't divide them regularly," she says.

Another great tip is to take advantage of the amended soil you've just put bulbs into - by overplanting these with fall lettuce. It doesn't disturb the bulbs underneath and …

"I'll be eating fresh salad through Thanksgiving," says Olsen-Haworth.