October is one of the best months for gardening in the desert. Here’s a look at what you can plant this month (almost anything!) plus how to take care of your new plants.
October is the month we’ve been waiting for! The monsoon (or nonsoon depending on how your summer was) is officially over. As the temperatures cool down, garden activity ramps up. It’s time to get new plants in the ground and spend more time enjoying your garden.
Here’s a look at what you can plant, how to dig the perfect hole, how to water new and existing plants, and more.
October Weather Outlook
You should notice a cooling trend, especially towards the end of the month. October’s average highs and lows in Tucson and Phoenix are about 10 degrees cooler than September’s. Additionally, the sun is less intense as the UV index continues to drop.
Here’s a look at October weather averages in both Tucson and Phoenix.
October Weather Averages (Tucson)
| High temperature | 86°F |
| Low temperature | 59°F |
| Precipitation | .72″ |
| Relative humidity | 33% |
| UV Index | 6.8 |
| Wind | 13 mph |
October Weather Averages (Phoenix)
| High temperature | 90°F |
| Low temperature | 65°F |
| Precipitation | .53″ |
| Relative humidity | 28% |
| UV Index | 5.9 |
| Wind | 6 mph |
If you live elsewhere, enter your city or town in the search bar at TimeandDate.com to find your monthly averages. You can find your average UV index at UVIndex.io.
What To Do in the Garden in October
The wait is over. This month you can finally do every gardener’s favorite activity — buy and plant new plants! October is one of the best months for buying and planting landscape plants.
November is a great month for planting, too, but you might find that nurseries have run out of that one plant you really wanted! (I’ve had this happen, have you?)
What to Plant in October
October can be the perfect time to plant almost anything:
- agaves and yuccas
- perennials
- woody shrubs and trees
- container-grown roses
- citrus trees
- deciduous trees (including fruit trees)
- cold weather annuals
- flowering bulbs
- cold-weather herbs and vegetables
It’s also time to:
- Sow spring wildflower seeds.
- Separate agave pups and replant.
- Divide non-woody perennials.
- Spruce up your containers with shoulder season annuals (dianthus, dusty miller, geraniums, petunias, osteospermum).
Here’s the short list of plants that ideally should not be planted now — cactus, palm trees, winter annuals, and any frost-sensitive plants.
Wait to Plant Winter Annuals
A visit to most nurseries this time of year will wow you with eye-popping displays of colorful annuals. If nurseries are selling them, this must be a good time to plant, right?
Unfortunately, the answer is “no.”
Nurseries put out annuals well before the best time to plant them. Marylee Pangman, Tucson’s leading authority on potted plants and author of Getting Potted in the Desert, recommends waiting until your nighttime temperatures are consistently in the mid-fifties before planting winter annuals. She’s found through years of trial and error that waiting for cool nights will reward you with happier, healthier, more beautiful plants. For many of us, this means waiting until next month to plant.
When in doubt… Wait!
If it’s still consistently hot (upper 90s to 100), wait until later in the month to plant.
Your plants will be less likely to suffer from transplant shock.
Planting Rule of Thumb
The rule of thumb when planting any desert plant is to dig a hole three times as wide as the root ball but no deeper.
University of Massachusetts Amherst Extension
If the plant is root-bound, score the root ball to cut through any circular roots.
Amending the hole is not necessary or advised. Backfilling with only native soil will help your plant develop a stronger root system.
Before you invest in any large or expensive new plants, here are
9 Things to Know Before Buying a Desert Landscape Plant.
Provide New Plants with Shade
Depending on the plant and its position in your yard, you may want to provide it with temporary shade. It’s still intensely sunny out there.
You can provide temporary shade with shade cloth or for small plants, do something as simple as placing a patio chair to block the sun. A patio umbrella works great but don’t leave it up unattended. Sudden winds can knock it over or turn it inside out.
Keep an eye on your potted plants and relocate as needed to account for the movement of the sun. Part of my south-facing patio, which is in full shade during the summer, is now getting full sun. My succulents (aloe, firesticks, lady slippers) take the additional sun in their stride, but I expose my less resilient plants to the sun gradually so they don’t get fried.
Watering New Plants
Water new perennials every two to three days for the first two weeks, then reduce watering to every week.
The University of Arizona recommends watering newly planted shrubs and trees according to this schedule.
| Weeks 1 & 2 | Every 3 – 4 days |
| Weeks 3 & 4 | Every 5 – 7 days |
| Weeks 5 & 6 | Every 7 – 10 days |
| Weeks 7 & 8 | Every 10 – 14 days |
Your first impulse may be to water any new plant well immediately after planting, but the Arizona-Sonora Desert Museum advises not to water cactus or other succulents for one month after planting in the fall.
Watering Established Plants
It’s usually recommended that you adjust your watering schedule to water less frequently in October. But when to do this depends on the weather. If you’re experiencing unseasonably hot weather, wait until the temperatures
have returned to normal before adjusting your watering schedule.
Continue to water deeply with each watering.
Not sure how to water adjust your watering schedule for fall?
These articles can help:
How to Water Desert Trees: How Often? How Much?
How to Water Desert Shrubs: How Often? How Much?
What to Fertilize
There’s no need to fertilize your landscape plants in October.
The exception is potted plants. It’s OK to fertilize any flowers, succulents, or other plants you have in containers.
What to Prune
This is not the best time of year to do major pruning since it encourages new growth. But you can prune any dead, diseased, or broken branches on shrubs or trees.
Leggy or overgrown perennials can be cut back by one-third.
And you can deadhead flowers and snip back annuals to encourage business and flowering.
Garden Pests & Diseases
You should find you have fewer problems with most insects this month. As the temperatures cool down, so does insect activity.
You may notice caterpillar activity, but they are mostly done eating and are looking for places to pupate.
Fun Fall Gardening Events in October
October is a big month for plant sales. There are so many, you may have to choose. Plant sales held this month in Tucson include:
- Arizona-Sonora Desert Museum Plant Sale
- Tohono Chul Plant Sale
- Pima County Master Gardener Plant Sale
- Native Seeds SEARCH Plant Sale & Pop-up Shop
There are also some family-friendly Halloween events held at local nurseries.
You’ll find an up-to-date list of gardening-related events in our Tucson Gardening Events Calendar.
Don’t live in Tucson? Look for Zoom classes. You can participate in these no matter where you live.
Did you enjoy this article?
Sign up for our weekly newsletter
where you’ll find more great info on creating &
maintaining a beautiful, carefree desert landscape.
Author Bio
Deane Alban is the creator of Southwest Gardener. She is a science writer with a bachelor’s degree in botany from the University of South Florida. Gardening is her lifelong passion. She’s been gardening in Tucson for 15 years.
