Gardening Tips for May 2025

---

Summer Annuals -  Zinnias Profusion Series, Petunias, Salpiglossis sinuata, Celosia, Lobelia .

Perennials - Leonotis leonurus, Lobelia cardinalis (likes water but worth it), Centaurea, Mimulus, Nemesia.

Shrubs - Rhododendron, Roses, Abutilon, Lantanas.

Vines - Clematis hybrids (may re-bloom when deadheaded), Mandevilla and Thunbergia alata (frost sensitive-used as annual).

Veggies - Zucchini, Tomatoes, Lettuce, Basil, Scarlet Runner Beans.

Extras - Metal Loop Stakes, Insecticidal Soap, Water Holding Polymers.

• Watering - We ask a lot of our plants. Here in our  Mediterranean climate we don't get the summer rains other areas do. Here we have approximately a six month period for possible rainy days followed by a six month period of drought. With this in mind, now is the time of year it’s super important to flush drip irrigation lines and check all emitters so that your plants will be happy throughout our hot/dry summer. Lawns-your lawn needs water when you walk on it and the blades do not spring back up. Water in short burst rotation-ex: 5 minutes water, rest fifteen minutes, 5 minutes water, repeat a few times. This allows time for the water to soak in and prevents run off. Roses-most roses (especially hybrid tea roses) do best with regular watering.  
• Pruning - After the flowers fade from spring flowering shrubs, you can prune Lilac, Rhododendron, Azalea, Camellia, Forsythia, Ribes, and Flowering Almond. There are different types of pruning depending upon what your intention is for your plants. When you would like to improve your confidence for pruning contact Mary for a Consultation/Tutoring Appointment. Ferns - if you have not pruned out the old fronds from your ferns prune now. Follow all the dead fronds down to the base of the stem and cut out the entire frond; being careful not to cut the new growth or accidentally break new fronds off. Fuchsias - pinch out tip growth to encourage more branching, which means more flowers later. Watch The Gardening Tutor Vimeo Video: How to Prune Fuchsias. 
• Fertilizing - After the flowers fade from Camellia, Rhododendron, and Azalea, fertilize with an acid fertilizer so they get a good start on the year it takes for them to form next year’s flowers! Gardenias appreciate regular fertilizing to keep flowering throughout the growing season. Use an acid fertilizer once a month for in ground plants and every two weeks (at half strength) for container Gardenias. Blueberries will appreciate some acid fertilizer this month too! Blueberries are great for large containers. Mulch blueberries with redwood compost and they will love it! Watch The Gardening Tutor Video: Two Quick Methods to Apply Fertilizer.  
• Fruit trees - although there is a natural thinning of fruit in nature referred to as “June drop”, it’s still a good idea to thin fruits a little before June drop. After June drop you can thin some more. The most important reason for thinning fruit is to lessen the weight on the branch so that you do not come out to your garden one morning and see an entire branch on the ground and a big gaping wound in your fruit tree. The other reason is to encourage bigger and more healthy fruit!
• Weeds! For more about how to manage weeds Watch The Gardening Tutor video: Weeds, How They Grow and How to Manage Them.
• Container Plants -  Apply at least a one inch layer of compost as mulch to container plants. Now is a great time to empty the potting mix from containers and replace with new mix. Also, add water holding polymers to help hydrate plants this summer.
• Pest Management - Control ants with bait. When you see ants crawling up and down your fruit trees, ornamental shrubs and other plants this is a sign that your plants may be infested with aphid or other insect pests. First, control the ant population. Also, wash off the aphids with a strong stream of water. If the infestation is still heavy use insecticidal soap (remember the follow up spray 7 to 10 days later-follow directions on the bottle). Sometimes, if you control the ants, the beneficial insects will show up to control those aphids and other pests for you.  
• Do you like Nasturtiums? Now is the time to plant your seeds or seedlings of Tropaeolum (Nasturtium). Remember that once you have established your plants you can start to hold back on the water and water less often. Watering Tropaeolums less creates more flowers. Watering more creates bigger leaves and fewer flowers. Sunflower seeds can be sown every few weeks now for a succession of blooms all summer.

Follow The Gardening Tutor on Instagram, Pinterest and Facebook. The Gardening Tutor How-To Videos are on our YouTube Channel.

Subscribe to The Gardening Tutor's Newsletter on our homepage so you'll know when the tips post. It's FREE! Plus, You'll Get Extra Tips for Subscribers Only. Also sign up to receive our BLOG Posts. We never share your email.

ALL CONTENT by Mary Frost (no AI).