The Plant Lady: Tips to get the best out of your garden with a little prep work

Fall is a busy time in the garden. Not only is it a prime planting season, but there are key chores to be done to ensure future garden success. Here are some tips on how to get ready for the next season and get the most out of your plants.

Planting

Besides spring, fall is an optimal planting season for perennials. The exception is frost-sensitive plants which may not be established enough if an early frost hits. Be careful when planting citrus, avocado and frost-sensitive salvias.

Fall is also the time to plant spring-blooming bulbs such as daffodils, hyacinths, irises, tulips and many more. Make sure to chill bulbs that require it. Hyacinths and tulips need to be put in a refrigerator for 8-12 weeks before planting. The key here is refrigerator — not freezer. Hyacinths will reliably come back each year without digging up the bulbs to chill. For more reliable blooms, look for species of tulips that have less chill requirements.

Winter vegetables can also be planted through fall. These include peas, kale, mustard greens, radishes and cauliflower. For a comprehensive vegetable planting guide check out sacmg.ucanr.edu.

Garden Cleaning

Before heading into winter, it is good practice to clean up plant debris. First, if any diseases have been suspected on your vegetables, it is necessary to pick up leaves and remove as many roots as possible. Some diseases can survive on plant material, so a thorough cleaning is desirable. Plant debris can also be a source of overwintering pests such as leaf-footed bugs and mealybugs. Minimizing places for these to overwinter can reduce the problems in spring.

Large pruning should not be done until plants have lost leaves, however some plants can be pruned to remove dead and scraggly growth. Be careful on frost-sensitive plants — it is best to leave old foliage to act as a blanket. Also be cautious on your once-blooming spring shrubs. Forsythia, camellias, wisteria and quince are examples of shrubs that should be pruned directly after flowering. If pruned in fall or later you run the risk of pruning off spring buds.

Mulching/Cover Crops

Mulching is a great way to get added nutrients into your soil, as well as helping to restructure it over time. Also, by adding a 3-to-5-inch layer of mulch over your soil you are keeping pesty winter weeds down. There are many options available for mulch. Compost is ideal because it contains the most beneficial microorganisms your garden soil needs. Straw and wood chips also will work (and can be quite inexpensive). Mulch also prevents winter rains from compacting the soil and allows earthworms to “work” closer to the surface of the soil.

To add nitrogen back to your garden, think about adding a nitrogen-fixing cover crop. Easy cover crops are fava beans, crimson clover and vetch. These plants have a symbiotic relationship with soil bacteria Rhizobia. The Rhizobium take atmospheric nitrogen and convert it into usable nitrogen. The key to achieving best results from a cover crop is cutting down and turning plant material under when the plants are in flower. If you wait until seeds/fruit form, the amount of nitrogen in the greens is almost completely depleted.

Apply Soil Sulfur

If you have high alkaline soils/water (pH 7.5 or higher), your soils can benefit from the addition of soil sulfur. If applied in spring and fall, over time the pH of your soil will decrease. Nearly all plants prefer an acidic soil, but some show their dislike of alkaline soils more than others. Gardenias, camellias, lily of the valley shrub and hydrangeas are a few. Decreased pH will turn your mophead hydrangeas from pink to blue. Also, if leaf tip scorch is an ongoing problem on saucer magnolias and Japanese maples, then a decreased pH will help to reduce this by allowing the boron to be flushed out of the soil.

Pest/Disease Control

Besides cleaning up plant debris, it may be necessary to spray to keep some pests and diseases under control. If mealybugs and scale have been an ongoing issue in your garden, applying horticultural oil can help eradicate them. The key is waiting until temperatures drop down into the 70s before spraying oil. Ideally, a few sprays will be applied before spring.

Late in the fall, your first application of liquid copper should be applied to peaches and nectarines to control peach leaf curl. Liquid copper can also be applied to shrubs that are experiencing leaf spot and other fungal issues such as shot-hole fungus. Be sure to coat surfaces of all branches.

Dividing Plants

When plants get too crowded it is sometimes necessary to divide them. A crowded plant will often result in smaller and fewer blooms. Not all plants can be divided of course, but ones that have fibrous roots or bulb structures can be. Note: It is best to wait until foliage has died down. Using a digging fork instead of a shovel can prevent shearing off of bulbs. If dividing a bulbous plant, then you can easily separate them with your hands once dug up. If dividing a fibrous plant such as a grass, use a serrated knife to cut through the root ball.