General Archives - Oceanside Garden

Growing Season

The USDA plant hardiness zones provide a very important piece of information to gardeners – how cold can the weather get without killing my plant. But this only touches on the tip of the iceberg. For many plants, even the USDA zone information needs to be modified by how wet it is at the time of the cold. For example, many plants will survive cold so long as they are relatively dry. Give them cold and wet and they will die.

Some plants will also provide an upper range in which plants can be grown. It is not uncommon to see a plant specified as zones 5 to 9. This is not really very useful at all. It is trying to convey that some plants cannot take excessive heat, or humidity or both. But hardiness zones and heat are not correlated for much of the country.

Mediterranean Climate

The biggest exception is the entirety of the West Coast (California through to British Columbia) where the Pacific Ocean has a huge influence on both the highs and the lows. The ocean provides an enormous stability. In winter we don’t get very cold, and in summer we don’t get very hot. Go inland just a few miles and things can be very different.

The previous paragraph contains an innocuous statement ‘in summer we don’t get very hot.’ That is one of the biggest impediments to what I can successfully grow here at Oceanside Garden. Many plants will remain dormant until the soil or the air have warmed up enough to spur them into growth. There is one plant I was trying to grow – Bauhinia purpurea, the purple orchid tree. It is a delight and would have been perfect except for one small problem.

Last year, the Bauhinia didn’t even break bud until August. It sent out one new shoot that grew to be three inches long and had seven leaves on it. When talking about a tree and with that kind of growth rate it is going to take a very long time to reach a decent stature. Plus, it is unlikely that it would ever set flower buds or that they would ever get to open before cold weather came in.

Unfortunately, that tree will be going on the compost heap in spring and a replacement found.

Death by Heat

To deal with this issue, a number of alternatives have been suggested. One comes from the American Horticultural Society that defines heat zones. They divide the country up into 12 zones based on the number of days temperatures rise above 86F (30C). For us that is almost never and thus we are zone 1. Zone 12 is for areas where this happens more than 210 days a year. Again, this is not useful because it defines when things will die and being in Zone 1, that means that nothing will ever die from heat here.

We have similar problems with tomatoes, which grow so slowly here that they often do not ripen. We need something that tells us about the temperature below which the plant will not fully function. For example, I have seen orchids often being described as sulking below 50F. Thankfully, I have a little space available in the greenhouse over summer and so there is room for a plant or two. I have even successfully grown plants over winter and had ripened fruit in March.

First and Last

Another useful piece of information is the average first and last frost dates. This can help knowing the length of the growing season – at least for plants that are willing to grow at temperatures barely above freezing. But these are averages. If you live by those, you may not take advantage of all of the growing season. Most people tend to stretch a little and cross their fingers.

Sunset attempted to fix all of these issues, at least for the West Coast. They divided the region into zones that consider the total climate: length of growing season, timing and amount of rainfall, winter lows, summer highs, wind, and humidity. This works for well-known plants that have been trialed in a lot of places, but growing members of the Protea family is still restricted to a few of us adventurous types. Let’s face it, nobody really knows much about how well they can grow in this country.

Lack of Data

The lack of heat is a concern for a number of the plants. There is little information on the Internet about the amount of heat they need to set flower buds. A few locations suggest they need temperatures higher than we get. So far, they appear to be wrong. A number of plants have bloomed, but I think the right question may be – do they bloom as well as they might in a warmer climate? I am OK with that. Part of the reason for wanting to try some of these plants is because we are in a warming climate and many native trees and shrubs are beginning to suffer.

This summer, the forests looked quite sad with a brown tinge over their normally bright green coats. It takes time for new trees to settle and become established. Just like many of the English gardeners – they planted for the future, not for today. Many of what are considered the great garden landscapes took 100 years to reach a modicum of maturity. We would not have had them if the gardeners of the time had not thought about planting for future generations and not for instant gratification.

Can I say I am planting a garden for the next hundred years? Perhaps not, but I do have a longer term view than most people.

O Tannenbaum

Ever since we moved to Oceanside, we have had a living Christmas tree. After Christmas, those trees are planted into the garden. For the first couple of years, it was easy – there was plenty of room and I still hadn’t decided how to utilize all of the space for a garden. That first year was a Blue Spruce (Picea pungens) and it soon found itself right in the middle of the cutting garden.

Quickly, one criterion for their selection became that they had to be of restricted mature size. A couple more pines and another spruce have since made the list. Then we decided that there was little reason why they even needed to look like a traditional Christmas tree. Why not evergreen shrubs? Last year, the height of our ‘tree’ was only 2 feet. Juniperus pfitzeriana ‘Gold Lace’ performed wonderfully.

This year, we have even departed from the notion of a traditional evergreen shrub, although we have in some senses regressed on some of the previous criteria – it is a tree and it can grow to 20′ to 50′ tall, with a width of 11′ to 15′. So what is different?

Well, it is a palm. Bismarkia noblis was a plant that we purchased a couple of months ago and has been in the house ever since. It is a little sensitive and only just hardy for us. It had also been grown as a house plant, so was going to need considerable adaptation to being outside and we decided to delay that until spring.

We had not planned to be around for Christmas, but with bad weather approaching, we decided to stay put. However, all of our Christmas decorations are in storage and so these are all the pitiful decorations we could manage. Still – it is the thought that counts.

The Complete list so far

2015 – Picea Pungens

2016 – Pinus thunbergii ‘Thunderhead’

2017 – Picea pungens ‘Gebelle’s Golden Spring’

2018 – Pinus parviflora ‘Cleary’

2019 – Pinus densiflora ‘Golden Ghost’

2020 – Juniperus pfitzeriana ‘Gold Lace’

2021 – Bismarkia nobilis

Bay Area Garden Tour

Last week I had to attend a conference in San Francisco. Not being comfortable about being squeezed into a small aluminum tube with 150 strangers of unknown vaccination status, we decided to drive from Oceanside, Oregon down to San Francisco. That being the case, it provided the perfect opportunity to visit some gardens and do some plant buying.

UC Davis Arboretum

On the way down, we stopped at the UC Davis Arboretum and public garden just outside of Sacramento. It is a wonderful walking path along what used to be the north fork of Putah Creek, but now is a controlled lake/waterway. The garden is split into different regional areas, most of them associated with Mediterranean types of climate. That means areas that focus on South Africa, Australia and New Zealand.

UC Davis - Lake walk — UC Davis – Lake walk

The walk around the lake is three or four miles, but we only did selected parts of it. Given that this is totally open to the public, this is a wonderful gift to the city. My only complaint is that it really doesn’t serve as an arboretum because almost nothing is labeled. Its ability to teach is limited by this. There are areas where signage does help people understand things like the bio swales and the role of certain plants.

UC Davis - Quercus mosaic — UC Davis – Quercus mosaic

UC Santa Cruz Arboretum

After the conference, we headed south along Route 1 to Santa Cruz. This surfing town is home to one of my favorite arboretums. At the Arboretum and Botanic Garden, the focus is plants that do well in Mediterranean climates and has a very extensive Australia garden and South African garden. The Australian Garden makes up over half of the total area and it has a wonderful display of Protea family members as well as many other trees and shrubs.

Everything is well labeled, and the plants are generally left to grow as they would in the wild. Little is pruned or shaped as they might be in a garden. The arboretum is associated with an extensive growing program. Many of the Australian plants come here first for trials to see how well they do in our climate and then they push them out into the nursery industry.

Some Rare Plants

They also have some plants that they are trying to work out how to effectively propagate. One of my favorite plants at this time of year falls into that category – Astroloma foliosum “Candle Cranberry”. What I would give to have one of these. While there we talked to Ferd, a volunteer in the garden and a director of the program. He talked about how it eludes them so far, and they have only managed to grow three from seed – of which he is the proud owner of one of those.

Ferd also showed us one of their prized possessions. The Wollemi Pine, one of the world’s oldest and rarest plants dating back to the time of the dinosaurs. This plant is being brought back from the brink of extinction as it was down to only 100 plants in the wild. The arboretum is now sending seed back to Australia for further conservation efforts.

Wollemi Pine with both Male and Female flowers

Attached to arboretum is their plant and gift shop – Norries. They sell many of the plants they propagate and at very reasonable prices. Plants can be ordered online for pickup, or just browse through what they have available. Many of them are in very limited supply, so I reserved some plants several weeks before the trip started.

UC Berkeley

The next day, we headed up the East Bay with the first stop being the arboretum at UC Berkeley. This is high up in the Berkeley hills overlooking the San Francisco Bay. Parts of the garden feel very old, with towering mature specimens, while other parts looked to have been more recently refreshed. Along with the Mediterranean climate areas, they also have an Asian area.

The Australasia section seemed to struggle growing many plants from the Protea family. While they did have some nice plants, the soil appeared to be somewhat unsuitable. Treating in some areas, you could feel a spongy soil that was holding a lot of moisture. Admittedly, it had been raining some in the past few days, but I also suspect they were adding supplemental water – something that these plants should not need, or even want.

Ruth Bancroft Garden

A little further north and east in the Walnut Creek area is the Ruth Bancroft Garden. This was once a private garden but now is open to the public and what a treasure it is. This is a dry garden and features succulents of amazing sizes. Many Aloes are in bloom right now, some with bloom stalks towering above you. Even those plants that are not in bloom will surely impress you.

They also have a great selection of plants available for sale, but not propagated from within the garden. While there are some plants that you can see growing and then buy, most of the plants available are not growing in the garden. The selection is in keeping with those shown in the garden.

The Journey Home

We journeyed home with 40 plants packed into the car. Most of them were 1 gallon sized, some larger and a few smaller. It always amazes me how many we can fit in. As we left the Bay Area, we were escaping from an atmospheric river. While there was lots of rain all the ways home, it was nothing compared to what they were expecting. The choice was to go up I-5, where the Siskiyou Pass reaches an elevation of 4310 feet or to go up the coast using US 101. Snow was predicted in the pass, and there were landslides at several places on 101. We chose to confront the snow and bought some chains just in case. Luckily, it was not too bad and we didn’t have to use them, but better safe than sorry.

Gardener’s Log – November 2021

What a wet November it has been, making it almost impossible to get out into the garden and do anything. Thankfully, there has been plenty to do in the greenhouse as seeds have poured in from around the World (South Africa, Spain, England, Australia). The only problem, and one that every greenhouse owner faces, is that you need a greenhouse at least twice the size of the one that you have!

Dahlia Rethink

The dahlias were a real disappointment this year. The extended dry period and our soils that are so sandy that keeping moisture in them is tough, made their growth stunted and very few blossoms. The ones that did better were grown in pots out the front of the house. Those had a much more water retentive soil and while I put them in pots that were too small, they did much better. With that in mind, all of the Dahlias got lifted this year, at least the ones that survived. Several were lost, but hopefully quite a few are salvageable.

Dahlia 'Phyllis Farmer' — Dahlia ‘Phyllis Farmer’

Normally, you should cut the tops off and then wait for a couple of weeks before lifting them. That was not in the cards. We had one somewhat dry day and that was my opportunity. I dug them up with tops still attached and then spread them out under the porch so that they get some protection from the rain that quickly returned. Hopefully, that will help to harden them off a bit before I start to clean them. Then they will go into some slightly moist wood shavings and into paper bags until next spring.

Symbiosis

I read an interesting article in the latest edition of Horticulture. It talked about the similarities of the human gut and root – I know, not the most pleasant of topics. But it made the connection that both rely on a symbiotic relationship. Roots, just like the human gut, cannot actually extract the nutrients they desire. They can absorb them when they are in the right form, but they rely on something else to do that for them. In the case of us humans, we have a large intestinal flora that performs that function. Roots use mycorrhizal fungi. The fungi extract the nutrients and make them available to the roots in exchange for being provided with sugars and starches that they need for their growth. Us humans provide a nice environment for the flora to live in and they also get to take as much food as they want.

But for every rule, there is an exception. In the plant World, the rule breakers are the members of the Protea family. They evolved in soil that did support mycorrhizae. Instead, they evolved along a different path and managed to come up with an alternative way to do it. They have special root structures, called Proteoid roots, that do have the ability to extract the nutrients themselves. This is both good and bad. It means that they can live in very impoverished soils.

However, mycorrhizal fungi also perform another function. They protect the plant from phytophthora species – the main reason why plants ‘damp off’, or get crown rot. This is why many people find it difficult to grow Proteas, because once your soil has phytophthora, it is almost impossible to get rid of it. The best defenses are sharp drainage, keeping moisture away from the crown of the plant and avoiding overwatering.

Plant Hunting

Planning is well underway for another plant hunting trip down into California during December. While this may not be the greatest time of year (spring is best), we need to go down to San Francisco for a conference and why fly with unvaccinated people when you can drive! Plus, you have in effect, a very suitcase with you. The UC Santa Cruz botanical garden will certainly be on the list, along with the Ruth Bancroft Gardens, UC Berkeley and UC Davis. The latter two are new for us, so that is exciting.

Plant Patents

There is a lot of bad information on websites about plant patents. This is what I understand to be true. A plant patent protects the developer of a plant for 20 years form the time the patent was granted. This prohibits any form of propagation without permission. So, even dividing an overgrown clump is not permitted. When you buy a plant, you have a ‘license’ for that many plants, and should you need to divide your clump, you may only keep one clump and the rest should be destroyed.

Will the plant police track you down for keeping two – very unlikely, but it is still illegal. Dividing is not the only way that plants can be propagated, and some of them become even more muddied. If you buy a patented bulb that produces bulblets, in theory you have to throw them away. Buy a strawberry plant and it will send out runners – you have to cut them off and throw them away.

New Plants

There are some plants that are worth having just because they are so improbable. One such plant is Massonia. I managed to get a bulb from a Pacific Bulb Society exchange earlier in the year and it has just started to bloom.

It never gets more than two leaves and that is in a 3.5″ pot. It would appear to not like frost, so it will probably remain in the greenhouse even after it has finished flowering.

Weather

The main focus for the month was wet – 19.68″ of it. That compares to 12.17″ last year. To compensate, those atmospheric rivers or warm tropical air pushed our average temperature up 2 degrees for the month at 50.4F. The maximum was 63.7 and the low at 38.1. Winds were slightly higher this year, although last year had a 57mph gust, whereas this year, we only managed 41.2mph.