July Gardening Checklist: Flowers & Flowering Plants
With the help of many gardening friends I have attempted to offer on these pages some useful information to help you with your own garden. Gardening is sharing. Any corrections, comments or suggestions are appreciated and will improve future information. Flowers and Flowering Plants are the focus of this NoteStream. Also see our NoteStreams on Fruit Trees, Edibles, and more.
"Sooooo Helpful - !" 5 stars by Deb
NoteStreams are readable online but they’re even better in the free App!
The NoteStream™ app is for learning about things that interest you: from music to history, to classic literature or cocktails. NoteStreams are truly easy to read on your smartphone—so you can learn more about the world around you and start a fresh conversation.
For a list of all authors on NoteStream, click here.
Read the NoteStream below, or download the app and read it on the go!
The information, dates and techniques in this blog are as accurate as I can currently offer. During the past three decades I have cared for, nurtured and observed tens of thousands of plants.
With the help of many gardening friends I have attempted to offer on these pages some useful information to help you with your own garden. Gardening is sharing. Any corrections, comments or suggestions are appreciated and will improve future information.
(See also Sweet Peas and Wildflowers)
A month for warm-season annuals, especially those that really love hot, hot, hot weather. The nights are warm, the days are long and sunny, and the temperatures are high. Keep newly planted annuals well watered until they are thoroughly rooted, Choices include ageratum, begonias, coleus, cosmos, dahlias, gomphrena, impatiens, lobelia, lisianthus, marigold, petunias, portulaca, salvia, torenia, verbena and zinnias.
Because of their quick growth and heavy flowering potential, annuals need more fertilizing than most other plants in the garden. Keep deadheading (removing spent flowers) from annuals to help them continue blooming abundantly.
Continue to keep azaleas well irrigated now that the weather is warming up.
Azaleas are shallow rooted and will dry out quickly. Avoid cultivating or allowing other plants to grow under or in competition with the roots of your azalea. This is a good month to leach the salts out of the root zone of your plants. This is done by irrigating the plant over and over again or by flooding the root basin several times to wash any accumulated salt below and away from the roots.
This is the first good month to dig, transplant and divide these.
Bearded Iris should be dug and divided about every four years (every two or three years for aggressive re-blooming varieties). If you are growing any of the new “repeat-blooming” varieties they may cycle again any time. Keep feeding these re-bloomers aggressively. Older “once-blooming” varieties can have their feeding reduced in half. Any fertilizer labeled for roses (but not with insecticides or other added ingredients) will do fine.
Bulbs, rhizomes, tubers, etc
(See also Bearded Iris, Dahlias, Cannas and Tuberous Begonias)
There are still several bulbs that will be in bloom now in Orange County. These include eucomis (Pineapple lily), galtonia (summer hyacinth), gladiolus, Gloriosa rothschildiana (gloriosa lily), haemanthus, hymenocallis and many true lilies. Crocosmia (formerly called montbretia) often bloom for a second time this month (the first bloom was probably in March). Caladium are doing great now.
Keep them well watered and fertilized and in indirect, but bright light. If done blooming and beginning to look a bit heat stressed, common white calla’s can be cut back now if you desire. Although not essential for plant health, a trim to near the soil line will freshen the foliage and help to encourage a second bloom cycle in late fall.
California Native Plants
Be very cautious irrigating most of our native plants during the summer.
Most of these are adapted to a winter wet – summer dry moisture cycle. Too frequent irrigations now (especially in soils with a clay content) will certainly cause problems.
Image by M. Dolly
You will probably be toward the middle or end of your camellia fertilizing for the year.
The first of three feedings to your camellia should have been applied about 4-6 weeks after it finished blooming. The second feeding is 4-6 weeks after the first and the final feeding is 4-6 weeks later again. Continue to keep camellias well irrigated now that the weather is warming up. Camellias are shallow rooted and will dry out quickly.
Avoid cultivating or allowing other plants to grow under or in competition with the roots of your camellia. This is a good month to leach the salts out of the root zone of your plants. This is done by irrigating the plant over and over again or by flooding the root basin several times to wash any accumulated salt below and away from the roots.
They should still be flowering well now.
Continue to keep them well watered in the hot summer weather, cannas do not like dry soil. As cannas flower you may notice that each stalk produces a cluster of flowers at the top. After this cluster finishes the stalk grows a few more inches and produces another cluster. In some varieties, this can go on for four or five clusters and last almost two months from beginning to end.
When the last cluster of flowers has finished, cut the entire stalk to the soil. This stalk will never bloom again and cutting it down will encourage more stalks, and flowers, to grow. Keep this process up all summer for the best results.
Clematis prefer cool roots, especially during the summer months.
If you can, grow another shrub directly to the south of your clematis to provide some shade over the roots. Alternatively, place a large decorative pot on the south side of the plant.
To insulate the roots even more and moderate the warm summer soil temperatures maintain a thick 3-4 inch layer of organic mulch over the roots at all times, especially now.
In the warm summer weather be sure to apply more frequent irrigations. Vigorous clematis varieties are still blooming. Keep them well fed with a balanced organic fertilizer to keep them going. If your soil is slightly alkaline (high pH) periodically alternate fertilizing with an acid product such as Cottonseed Meal. If you are growing a spring-only flowering variety (not as common in Orange County), these should be pruned soon after their spring bloom is finished, which may be this month.
Dahlias (tuberous types)
Plants should be in full bloom, robust and vigorous.
Regularly cut off spent blooms to make the plants both look better and set more flowers. Keep the taller varieties carefully staked to prevent the heavy canes from toppling over. Heavy natural cane bamboo stakes work well. Water regularly and deeply. Flooding the soil works best; overhead watering will cause broken stems and mushy flowers. Missed waterings now will cause gaps in flower development later in the season.
Fertilize them regularly throughout their growing and blooming period. Use a liquid or granular organic fertilizer that is low in nitrogen and high in phosphorus. Fish Bone Meal is excellent. If powdery mildew appears on the lower leaves use organic Neem oil or E-Rase.
Your plants should still be blooming well.
Keep fertilizing regularly with a balanced fertilizer or one slightly higher in phosphorus, to promote blooms. Proper watering becomes critical at this time of the year, especially for those plants in hanging baskets. Water early in the morning or in the evening and check their soil moisture most every day. Never let the soil dry out completely.
During any particularly dry, hot or windy period a couple of mistings of the foliage is very beneficial.
Image by Audrey
If the soil is already moist from an early morning watering (best), be careful not to soak the soil again or you may encounter root diseases.
Groom the plant periodically by removing dead flowers and any developing seedpods. Keep watching for early infestations of Fuchsia Gall Mites this month. These nearly invisible pests are a serious threat to fuchsias. Look for any signs of puckered or distorted new growth. If you discover any, pinch it out and dispose of it immediately. A pesticide treatment is usually required. Be careful not to burn your plants. Sun is getting a little higher in the sky and the days are longer.
Gardenias should still be blooming and growing pretty well this month.
Keep them well fed through the summer months. Use a fertilizer with trace minerals, such as most organic types and alternate this with an acidic formula to keep the pH down. If the leaves are showing signs of green veins with yellow areas between the veins, especially on the new growth, they need additional iron. Iron is a supplement to the regular fertilizing program of your gardenia.
Apply a thick organic mulch under each plant to moderate the soil temperatures and retain moisture.
Gardenias are shallow rooted and will dry out quickly. Avoid cultivating or allowing other plants to grow under or in competition with their roots. This is a good month to leach the salts out of the root zone of your plants. This is done by irrigating the plant over and over again or by flooding the root basin several times to wash any accumulated salt below and away from the roots. Gardenias do not like hot dry winds. If these threaten do what you can to shield the plant. A light misting and syringe of the leaves also helps.
This group includes Ivy geraniums, zonal geraniums (also called “Common” geraniums),
Martha geraniums and the various scented geraniums, but does not include true geraniums (sometimes called “Hardy” geraniums), which are discussed under Perennials. Ivy and Zonal types are still blooming well now. Keep up with removing spent flowers regularly to encourage more bloom.
Martha types have finished up their big bloom for the year.
Unlike Ivy and Zonal types these are not everblooming plants. With regular deadheading, a bit of shade in hot inland gardens and continued feeding you may be able to coax a few more blooms through summer. Ivy and Zonal geraniums do not like heavy pruning. To keep the plants shapely and vigorous for a longer period of time prune back a few long stems every month or so from now through fall, but never very many at one time.
Continue fertilizing all geraniums, except most scented types, regularly with a balanced fertilizer. Geraniums prefer a slightly acidic soil, so periodically alternate feedings with an acid fertilizer, such as Cottonseed Meal. Martha’s are done blooming for the year. Budworms may still be attacking the developing buds and new leaves. If necessary, spray with BT on a regular basis.
A few may still be in bloom.
Even dried hydrangea flowers can be attractive on the plant as they change color and take on a unique appearance. Keep feeding them in order to produce more new growth (which will bloom next year). Remove any flowers that have faded by pruning as far as half way down the stem below the faded flower. Only prune stems that have flowered this season, leave all other stems alone since they will flower on their tips next season.
Orchids (Outside Grown)
Keep feeding cymbidiums with high nitrogen to promote growth.
Be sure to keep them well watered in the warm summer months.
(See also Bearded Iris, Bulbs/Rhizomes/Tubers, Cannas, Dahlias, Fuchsias, Geraniums, Ornamental Grasses and Tuberous Begonias)
If you are planting perennials this month be sure to keep them well watered as these young plants head into the warm summer months. Also, try to avoid overgrown or root bound plants, as they will be harder to establish. Keep fertilizing your perennials. The frequency and amount will depend upon the formulation that you are using. If you have been building up your soil health your fertilizing duties will be much reduced.
Most of your time in the perennial garden now will be occupied with general cleaning, some trimming, lots of deadheading and mostly enjoying your garden.
Irrigating your perennials now is important. The heat of summer is bearing down on these plants and the plants will respond well to careful irrigations. Removing the many spent or old flowers regularly will help them to produce more new flowers. Add these to your compost bin. Sub-tropical perennials are at their happiest now and over the next couple of months. This is a good month to plant these heat lovers too.
Make the last pinching of the tips of the new growth early this month.
After this, do not pinch any more this year. Keep fertilizing the plant often with a well balanced food to encourage growth. Watch for whiteflies and treat as needed. Protect the plant from high winds to avoid breaking the stems. Keep the plants well watered.
Some roses, particularly old-garden roses, also called heirloom roses, only bloom on their “old wood”.
What this means is that they only produce flowers on the tips of the branches that were left in place from the previous summer. By contrast almost all modern roses bloom on “new growth”. If you are growing any of these types of roses (popular examples are ‘Cecil Brunner’, ‘Grus an Auchen’, Reine des Violettes’) they need their annual pruning immediately following their big spring bloom. If you didn’t do it last month, this pruning may be about now. Do not prune these varieties again in the winter or you will eliminate most of the flowers for next year.
Do not use soil-applied fertilizers combined with systemic insecticide.
These products are very disruptive to soil life (beneficial microorganisms, bacteria, mycorrhizal fungi, earthworms, etc.). Many rosarians also believe they reduce the vigor of the rose.
Although many roses will be blooming well, the big spring show has moved into a bit of a summer slowdown, especially in inland gardens. The flowers will be a bit smaller and they will open a bit faster.
Granular, well-balanced, organic fertilizers work especially well for roses and most of these will encourage beneficial soil life.
Keep deadheading roses as they fade. Stay on the lookout for pests. The primary culprits now will still be Rose Slugs (see next) and spider mites, which like the warm, dry summer temperatures. Rose Slug is still common now. If you have them, you will see lots of irregular holes eaten through the leaves.
If the situation is severe a “skeletonized” appearance to the leaves will be common. Control these with organics like Neem oil or Pyrethrin sprays. The applications must be thorough, frequent and applied to the undersides of the leaves.
Disease problems, especially in inland gardens, should be minimal through the rest of summer.
Irrigations should be frequent and deep now as the weather warms and the days lengthen. Check the mulch layer beneath roses and add any more as need to keep the roots cool and reduce watering requirements. Hose off the foliage of roses frequently. Contrary to popular myth, this will actually reduce the likelihood of powdery mildew and discourages spider mites as well
These should be done and pulled by now.
If, by chance, you still have a few hanging on, enjoy them while you can.
If you need more, potted blooming plants are now available in nurseries.
Plants should be in full bloom by now. Most tuberous begonias produce both male (single) and female (double) flowers separately on the same plant. The double flowers are much showier and many gardeners pinch off the single (male) flowers as they appear. Keep fertilizing regularly. They are heavy feeders, especially in containers. Use a well balanced fertilizer and periodically mix in an acid fertilizer, to keep the soil pH low.
Tuberous Begonias (Cont.)
Keep them well watered, but not soggy.
The soil should be rich and well-drained. The surface of the soil should dry slightly between watering. If in a breezy location, staking upright varieties with a small bamboo stake will reduce the possibility of breakage. Pinch off faded flowers regularly and rotate container grown plants to insure even growth. If powdery mildew appears treat it by improving air circulation around the plants. Usually this will correct the problem, if not use a fungicide.
It is the wrong time to be thinking about wildflowers now.
However, if you will be planting again this winter keep the area free of weeds between now and then. If the area has no other plants in it do not water. Irrigations will only encourage weed growth.
On established plants, your first pruning should have been made last month.
No need to prune now. You’ll prune again next month. Established wisterias need only an occasional deep summer watering and little, if any, fertilizer. However, iron is occasionally needed to correct chlorosis. On young plants, continue guiding the long, twining stems carefully in the direction that you want. Also on young plants, be sure to provide plenty of water and fertilizer it to encourage quick coverage and deep roots.