Barbara Olsen Garden Design . Gardening . Consulting

08/16/2026

08/16/2026

07/29/2026

Happy Monday! When hot weather is on the way, it is best to water early in the morning. Spot watering at the base of plants is also a great way to ensure plants get the moisture they need without causing mildew.

What do you think is the hardest part of gardening during a heat wave? Please stay cool and comment below!

07/29/2026

🌡️ Heads up, gardeners — a major heatwave is moving into parts of California this week, and your garden will feel it too.

When temperatures climb past 100°F, plants lose water faster than their roots can replace it. Expect wilting, flower drop, and even sunburned fruit on tomatoes, squash, and pumpkins.

A few things that help:
🌿 Water deeply (not just often) so moisture reaches the active root zone
🌅 Water early in the morning
🍂 Mulch to cool soil and reduce evaporation
⛱️ Temporary shade cloth for young or vulnerable plants

Tomatoes may stop setting fruit in extreme heat but often bounce back once temps moderate — don't give up on them yet!

Get the full rundown on protecting tomatoes, beans, corn, and squash from the heat 🔗 https://ucanr.edu/blog/backyard-gardener/article/when-your-garden-gets-too-hot



Photo credit: Adobe Stock by tonifrito

Photo description: A dense planting of squash fills the frame, with large dark green leaves wilting and drooping from thick stems in the midday heat. Straw mulch covers the ground between plants. A few yellow blossoms are visible among the stressed foliage.

07/22/2026

We have a Facebook group for Pacific Horticulture that we hope you will join. We just posted this picture for discussion, a lush looking garden full of bromeliads that may not seem like an appropriate garden for our summer-dry climate. That is the question.

07/22/2026

It’s California Invasive Weeds Awareness Week (CIWAW)!

Begun in 2004, this annual event focuses on the problems caused by invasive plants (w**ds).

Let’s start with a big, spiny problem - yellow star thistle (Centaurea solstitialis).

Despite more than five decades of documented control efforts, this w**d covers an estimated 15% of California!

This tenacious thistle is a textbook example of an invasive species, a non-native that outcompetes native species and reduces habitat diversity.

🔹First, it makes two kinds of seeds- plumed seeds that the wind can carry long distances and plumeless that fall near the parent plant, (thousands per plant). Both types can travel even farther on vehicles or in contaminated hay.

🔹Second, those seeds germinate with the first fall rain and build a long tap root, giving them a head start over other annual plant species. Plus the blue to grey-green foliage holds on tight to moisture they have pulled from the soil.

🔹Third, those spines say "don't touch me!"

It is toxic to horses. Cows and sheep will consume it before the spines develop and goats don't seem to mind the spines. However, injury to the eyes, nose or mouth of livestock is still possible.

The best time to remove it is before those spines appear.

If you can identify the rosette, you can hoe it early in the spring.

Between rosette stage and starting to bolt, if the ground isn't too dry, you can dig or pull the plant.

A stand-up w**der tool and litter picker can help create distance between developing spines and your face.

If you can't pull it, at least cut it off at the base.

Wearing proper Personal Protective Equipment should include thick gloves when handling these plants.

Removal will be a multi-year plan.

For more information: https://ipm.ucanr.edu/PMG/PESTNOTES/pn7402.html?src=302-www&fr=4684 and research from the California Invasive Plant Council:https://www.cal-ipc.org/docs/ip/management/pdf/YSTMgmtweb.pdf

04/04/2026

Siberian iris, spuria iris and crested iris are easy-to-grow perennials bloom in spring. Here's expert advice on choosing and growing them.