Heat Wave Report

 Another heat wave came and went. So how did we do? Inspecting the garden I would say we fared well. Maybe we have drought-adapted gardening down, then again maybe my confidence is misplaced and we are in unchartered territory. I feel the latter is probably more likely and that many surprises are still on our horizon. Much of the garden looks fairly good right now, although a few concerns have me scratching my head. Huh? Why is this plant doing that?

We had a mild and wonderful spring with rainfall and sunshine in seemingly equal measure. Therefore we did not water anything until the week before the (record breaking yet again) heat wave. We are grateful watering began so late in the year. In addition, we are not watering nearly as much as we once did because as plants grow and are established, they cover the soil beneath much more thereby creating a living mulch, i.e., making their own shade. Mulching over the years with either wood chips or gravel or compost has helped tremendously with water retention. I see the biggest difference with wood chips. The veggie garden is a great example, and I'll publish a whole post dedicated to that very soon. Also, winnowing stressed and unhappy plants from superstar survivors over the years has made a difference and while it may mean that I don't have all the cool plants, I do have a lot of great ones that can take the heat. Probably. That depends on future weather patterns, of course. Winter cold and wet is, of course, the other consideration.

The facts are that we started systematically watering in late June and early July with sprinklers. I hand-watered the sunniest, driest areas so I can direct water to only those plants that want/need it. Watering before the heat wave helped a lot, during not so much, though we did run sprinklers periodically for our bird friends to cool off. I hand-watered all containers either in the morning or evening every other day for a week and moved the smallest, most vulnerable containers into shade for the duration of the worst heat. It began on the Fourth of July and ended (though we're still very hot) on July 10. The hottest temps hovered the 104 mark and we set records for hottest days ever on five of those days.  

Here is an overview of some swell looking plants as well as a few that have looked better, frankly. 

The outer edges of the labyrinth garden are looking pretty good. Self-sown Verbena bonariensis is everywhere this year. The Macleaya cordata or plume poppy is happy with the heat as are Arctostaphylos pumila and Ceanothus cuneatus 'Adair Village'. Festuca 'Beyond Blue' is also loving it.

My new favorite superstar Mirabilis multiflora commonly known as Colorado four-o-clock has spread (from a single tap root) to about a 6'-wide mass of prettiness. This is completely deciduous and forms a huge root below the surface which I'm sure is what enables it to survive in its home of hot south-facing reflected heat from our metal-sided house with no supplemental water.

Right next to it is Atriplex halimus, saltbush. This is evergreen, edible, prune-able and heat adapted. Fabulous large shrub that can get quite large at about 8' or so tall. This is my second plant, the first was uprooted by moles and died off but I saved cuttings and have many potted plants in the greenhouse.

Here is the area where the above two plants are located. This faces south and as you can see we have metal siding on our home. Left to right are Eryngium giganteum 'Miss Wilmott's Ghost', Cistus x platycephalus, Mirabilis multiflora, behind it Panicum 'Cloud Nine', Atriplex halimus, the fluffy pinkish low plant is Dorycnium hirsutum and it's climbing into Callistemon viridiflorus. All of these plants can handle the heat.

Many penstemons did great in the heat. This is supposed to be Penstemon 'Firebird' but I think it was mislabeled. It gets little water and is a mass of beauty. Most other penstemons are equally happy, our natives especially.

Lupinus albifrons and its silvery goodness had no problem sailing through high temperatures. These are not even a year old and have grown quite large.

Romneya coulteri, tree poppy or fried egg plant is a California native with a large presence. It loves the heat and has rebounded nicely from the other extreme of January's record cold temperatures.

Eriodictyon californicum, commonly known as yerba santa, is an evergreen plant from California and Oregon. I bought it at work last year and while it should be evergreen it suffered horribly this winter and was considered dead. It rebounded nicely as you can see and I look forward to watching it grow in time. I must note that where this is planted, one of our newest beds planted on Halloween last year, was hit hard in January as unestablished plants are vulnerable. All have rebounded, I am happy to report, with only one casualty, Ceanothus sanguineus.

Phlomis russelliana (and likely other species of phlomis) could care less about the heat. 

Madia elegans, an annual wildflower, loves the heat as well.

I am quite surprised at how well Diascia 'Coral Canyon' is growing and spreading.

Brachyglottis greyi is an evergreen shrub from New Zealand. It has silvery foliage with the undersides especially luminous. A great plant for hot dry sites. This has not shown any signs of distress in extreme heat or cold and I do not irrigate in summer. It reaches about 3 - 4' tall and maybe a little wider.

A no i.d. opuntia from my mom. While I don't love this genus, its cheerful yellow flowers are great and it is quite happy in a most difficult site.

Penstemon kunthii is also loving the heat. I thought I lost one to the cold this winter but it came back. Others I planted recently have really taken off. Usually I have to water this one come July/August for it to look its best but this year, I haven't had to water it at all.

Just pretty, airy Verbena bonariensis.

I am sorry so many of you lost grevilleas to our epic winter. I know Grevillea 'Neil Bell' was a favorite of many of you and with good reason. For some reason mine was spared and it going out of control with SO many flowers. It's never bloomed this much and is bigger than ever at about 7' x 10'. Mine is in full sun, sloped ground, south facing, plain old field grass soil - unamended - and it loves it.

Cotinus or smokebush (this is C. 'Grace') are very drought adapted and are very happy this year.

Veronica longifolia, left and Teucrium hircanicum in the meadow garden. The latter can be a prolific reseeder but it is one tough plant. The veronica is as well, though it appreciates summer water periodically.

Olives also love the heat, of course. I have a row of four Olea 'Arbequina' that are established and very happy with the heat. I planted them in January 2016 and the following winter we had one of the worst winters I've ever experienced and they all died to the ground. But they all came back from the roots - even after being in the ground less than a year. Very resilient.

Many other plants not pictured here did predictably well during the heat such as Teucrium chamaedrys, Geranium macrorrhizum, Quercus hypoleucoides, hebes, many native plants such as Gaultheria shallon, Physocarpus capitatus, Polystichum munitum, Lonicera involucrata, native grasses and much more.

A FEW ISSUES

In addition to drying out the soil, hot temperatures can also scald foliage or bleach it. Here (hard to see, apologies) Tetrapanax papyrifer foliage was fried up top, bleaching out and becoming discolored and dying. Lower down with protection from surrounding foliage it looked fine.

Agave ovatifolia 'Frosty Blue' with sunburn was a bit surprising to me. It literally happened overnight.

One of two Stewartia pseudocamellia got a bit crunchy, but this is not entirely surprising as these do like water and this is a fairly young tree.

A few of my remaining cistus have been displaying curious die-off. This one, Cistus x platycephalus, is one of three planted at the base of our home on a south facing reflected heat bed. The reflected heat is no problem for them but one day I noticed half of this particular plant was on its way out. I cut it back and indeed its branches were crispy and dead. I have no idea why it did this. Others had one branch here and there die off in different areas of the garden. I think the January cold was too much for many of these plants - especially if they are planted in heavy soil.

Speaking of reflected heat, this area is always an issue in a heat wave. Although on the north side of our home it is in full sun from spring until autumn. The concrete retaining wall, gravel and house just out of sight on the left all retain heat for hours after the sun goes down. During the day on a 103-degree afternoon, these plants can fry, especially for some reason the erica or heath, the dark green mounds to the left of the cascading Clematis recta 'Purpurea'. This photo was from late June before the heat hit, today it's a bit crunchier and browner.

Every year for the last three or so years one section of Ceanothus gloriosus does this in July/August. The light areas are dead, crispy foliage and it happens seemingly overnight. Areas to either side of it have healthy, lustrous green foliage unharmed by whatever is doing this and the same plants elsewhere in the garden are also healthy. The stems are pretty much alive but I have been cutting them back as it's so unsightly. I may rip this section out all together but it's quite large, so I hesitate. Something is going on, perhaps underground. I see no evidence of mole activity. Other Ceanothus gloriosus are in more sun than this and are fine. It's a mystery but could be weather related, or perhaps a pathogen in the soil. Chime in if you have ideas.

In the hottest parts of the garden many sedums bleach out and become yellow when they are usually deep green. This is Sedum oreganum at the southern edge of the labyrinth garden. No amount of irrigation can prevent this from happening, it's just due to exposure to hot temps. A shade cloth would probably help but I'm just not that gardener - one to go protecting plants in extremes in a two-acre garden. 

Other plants I noticed had bleaching/yellowing are Lavandula stoechas, Carex comans, Sedum divergens, and Sedum spurium (syn. Phedimus spurius).

A few of my manzanitas have had surprising damage. This is a random branch of Arctostaphylos 'Saint Helena' that is pretty much fried. A bit of green on there and as it's out of arm's reach I'll leave it to see what happens. 

In fact, many of its leaves have crispy ends. I can't really make out why this happened. Perhaps it's due to reflected heat from our metal siding on the house but it's never really done this before. Perhaps this is winter damage showing up late in the game. In addition to this the annual yellowing of the interior leaves is intense this year for a couple of these. Maybe it's that we had such a mild spring with a lot of tender growth followed by an abrupt heat wave. Chime in if you have theories. The plants are alive and well otherwise and most other arctos are super happy.

I also had an Arctostaphylos 'Sentinel' with a rather large branch totally die a couple of months ago. After removing and seeing the interior wood there seemed to be a little bit of discoloration but not anything alarming. Another smaller branch died last week, too. I have not done anything different, rather I think it's our weather patterns and certain stresses are showing up now. Things that make you go "hmmmm...?"

Here is a link from Oregon State University Extension about helping your plants survive heat stress.

A FEW WIDE SHOTS

Overall the current selection of plants seems to be pretty happy. Santolina 'Lemon Queen', a few native buckwheats, Callistemon 'Woodlander's Hardy Red', Agave neomexicana, Phlomis russelliana, Baptisia australis, Penstemon pinifolius and others are quite happy in this, the hottest and driest part of the labyrinth garden. I do notice Ozothamnus 'Sussex Silver' and the other, O. 'Silver Jubilee' both appreciate a little summer water to look their best. That's my soil, though - very well drained so in heavy soils it might not need it.

The edge of the meadow with Amsonia hubrichtii, Anementhele lessoniana, Achillea millefolium, Digitalis ferruginea, Epilobium 'Solidarity Pink' (syn. Zauschneria) and others. This all receives very little water, I've watered twice so far this year in this area and that's by hand.

Tall ephemeral plumes of Stipa gigatnea mixed in with faded seed heads of Sidalcea campestris and a cardoon for a little fun. On the right Romneya coulteri stands tall.

Wide shot on a hot summer day.

Around the fire pit, Festuca rubra 'Patrick's Point' and Muhlenbergia rigens (deer grass) add a little fine texture. The deer grass, which is normally evergreen, took a hit this winter but is, as expected, filling in nicely. Both grasses are incredibly drought adapted west coast favorites.

More Muhlenbergia rigens with Stipa barbata in the background doing its magic thing.

So what about irrigation for the rest of summer? The shade garden will certainly receive at least weekly water (FM's favorite garden, after all), other areas here and there. Honestly it will probably be containers, a few perennials and ferns, some woodland plants, plants less than a year old and the vegetable garden of course. How much and with what frequency depends on how hot we are and as of now it seems we're in for a hot July and August. We are a summer dry region, after all, so we expect no rainfall. It's the super high temperatures that cause riff raff. 

A parting shot of our bee hive this year - doing a bit of cooling off in a heat wave. They hang out at the entrance when it's too hot to be inside. While I read that honey bees are now considered invasive species and pests by many, I honestly think there is enough in our garden to satisfy the myriad of native insects and these guys. Perhaps in an urban garden they might outcompete native bees, but here there is so much for everyone. It's funny, we were just fighting to save the honey bee only a couple of years ago. Just my two cents for what it's worth. Constantly learning and adapting.

While this June was dreamy and lush as far as gardening is concerned, July brings brown "lawns" (the only green bits are the weeds and even they are dying), scorching heat (mild compared to much of the world right now, sadly), soil drying out super quicky and another round of doubt about plant resiliency. I had a long conversation with a customer recently about her Western red cedar, Thuja plicata, dying off and what can she do about it? I see many of our native Douglas fir, Pseudotsuga menziesii, also showing signs of stress in the form of needle drop, scorching, excessive cone production and limb die off. These established trees will probably continue to show signs of decline and their territories could march northward as climate change continues. Even the big leaf maples, Acer macrophyllum, are having epic seed production years, I think possibly a sign of trying to reproduce before dying off. This is part of the "unchartered territory" I mentioned earlier. We just don't know but we should pay attention. 

While I have moments of despair there are more moments of joy the garden brings me. With a little creativity we can tweak our gardens towards resilience and maintain beauty. The gardens of tomorrow may look different than that of our parents' generation but for those of us who love gardening, we'll find a way no matter what.

That's a wrap for this week at Chickadee Gardens. As always thank you so much for reading and commenting. And for those of you who came to the Cistus Summer Extravaganza and said hello to me and encouraged me to keep on blogging, thank you. That means the world to me. Stay tuned as I'm off on a Puget Sound adventure with about 100 other garden bloggers this weekend for the annual Garden Blogger's Fling. We're off to such infamous gardens as Dan Hinkley's Windcliff, Rhododendron Species Botanical Garden, Port Defiance Zoo and many others. Stay tuned.