A beautiful way to add color to your garden in winter and early spring is to plant hellebores.  These perennials grow low to the ground in clumps usually no more than one- and one-half feet high, with distinctive leathery, dark-green leaves.  Their flowers, about two inches across, appear in clusters that either face upwards or droop downwards.  Old-fashioned varieties flower in shades of white and green, but newer hybrids broaden the hellebore color spectrum to include shades of pink, purple, yellow, red, gray and black, in single or double forms, and there are even some spotted and striped varieties.

Hellebores like high shade and thrive under deciduous trees in well-drained fertile soil.  Good locations include the north or east sides of walls, and underneath high-branching trees.  Like many flowering plants that do well in shady conditions, hellebores do need light in order to bloom profusely, so the more sun you can provide them in a shady location, the more flowers you will have.  While a daily blast of afternoon sun in late summer and fall may scorch their leaves, they will still bloom beautifully in the spring.

An added bonus is that hellebores are deer-resistant and do not freeze in cold winters.

Happy hellebores will self-sow if their flowers (which are actually sepals, rather than petals) are not cut off after the blooms have faded; seed pods will form, eventually (usually in July) dropping their seeds close by the mother plant, where new baby plants will develop.  Because the new plants develop so close to the original plant, it is a good idea to thin the babies out or transplant them.

Fertilize in September, when they are forming the buds for their winter & spring flowers.

Right now, when you are raking up leaves and cleaning up your garden, is a good time to cut off last year's hellebore leaves (most hybrid hellebores are stemless).  If there are no buds showing yet, you can simply grab the leaves by the handful and cut them off.  If the plant has started to bud, just cut off last year's leaves.  It is not absolutely necessary to do this, as new leaves will cover the old ones, and the old leaves will eventually turn brown and can be swept away by hand.  If you are in doubt, it is safe to cut anything (stems or leaves) that has turned brown.  Cutting them off does make yard raking easier, as once the leaves are gone you can rake right over the plant.  This gives the garden a cleaner look now and also later, when the new leaves and buds appear and the plant blooms.

If you want a hellebore that blooms a particular color, it is best to buy the plant while it is in flower, so you know you are getting exactly what you want.  That plant will always bloom that particular color, but there is no guarantee that its seedlings will follow suit.     

While some early-blooming hellebores are already in flower, most will bloom between late January and early April.   Look for them at your favorite nursery.

UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area, visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu (preferred) or call (530) 538-7201.

Plummeting winter temperatures often lead to frost damage in plants.  The damage occurs when ice crystals form within plant tissue, damaging their cells.  Leaves and tender new growth are usually affected first.  Initially, they will appear wilted.  Then the wilted growth will turn brown or black and eventually become crispy.  This means these affected parts of the plant have died.

It is tempting to remove frost-damaged plant growth immediately, but dead material should be left on the plant until the full extent of the damage is apparent in the spring.  There are several reasons to wait.  By allowing plenty of time for new growth to appear, the extent of any damage will be clearly apparent and it will be less likely that you will accidentally remove living tissue that survived a freeze.  Additionally, dead material can actually provide an insulating effect and removing it too soon may expose additional tissues to future freezes.  If you prune out dead material before another freeze hits, it is more likely that an even greater portion of the plant will be killed.  In Chico and nearby areas of the valley floor, the danger of frost is usually over in late April, so it is prudent to wait at least until then, or later, before doing any pruning.

In citrus, if hardier growth (such as twigs or wood) has not been seriously damaged, it is normal for dead leaves to be rapidly shed.  If the frost-killed leaves remain on the plant, this is an indication that twigs or branches have been seriously damaged.  If larger branches or the trunk of a tree sustain cold damage, the bark will split and dead patches of curled, dry bark may appear.  If a young citrus tree has been killed nearly to the ground, inspect it closely to determine if the damage extends below the union.  The union is the junction where the fruit-producing part of the tree was grafted onto the rootstock.  If new growth comes only from the rootstock, the tree will no longer be true to the type you originally planted and will usually be unproductive.  In this case, the tree should be replaced.

The only thing that should be done immediately after frost damage has occurred to citrus and other woody plants is whitewashing.  Whitewash should be applied to the trunk and exposed limbs.  This protects the bark from sunburn, which is more likely to occur if a plant becomes defoliated.  Frost-damaged plants are more susceptible to disease and insects, and sunburn increases this susceptibility.  To make whitewash, mix equal parts of white interior latex paint with water.  If the area to be painted is particularly rough and fissured, a thinner mixture can be applied for better penetration and coverage.

It is also important to note that frost-damaged plants are unbalanced:  although their leaves have been reduced, they still have the same root system.  This can result in extensive new growth over the entire plant.

To ensure that the plant reaches an acceptable balance between its leaves and its root system, the new shoots should grow at a moderate rate.  It is recommended that little or no fertilizer be applied to these plants initially, and they should be irrigated less than usual until they have returned to a normal appearance.  Too much nitrogen fertilizer, for example, can encourage sucker and water sprout growth, while too much water can damage roots.

Of course, it would be preferable to prevent frost damage from occurring in the first place.  To read more about preventing frost damage and many other gardening topics, visit the UC Master Gardeners of Butte County website.

UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area, visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu (preferred) or call (530) 538-7201.

Freezing temperatures damage plants by causing ice crystals to form in their cells.  Frost-damaged vegetation withers and turns a dark brown or black.  Ice crystals can also form in citrus fruit, causing juice vesicles inside the fruit to rupture and the fruit to dry out.  Although frost-damaged fruit is edible after a freeze, it is susceptible to decay and often becomes unusable soon after the damage occurs.

Leaves, green wood and fruit are more frost sensitive than hard wood.  Ripe fruit is more cold tolerant than green fruit because sugars in the juice act like antifreeze and lower the temperature at which it will freeze.  Fruit is slightly less cold tolerant than leaves, and trees with fruit are less tolerant than trees without fruit, so in addition to preventing damaged fruit, picking fruit before a predicted freeze will not only save the fruit, but will help protect the entire tree as well.

Different types of citrus vary in cold hardiness.  Mandarins and kumquats are the most cold hardy varieties of citrus trees.  Mature mandarin trees, for example, can tolerate temperatures down to 20° for 4 hours before serious damage occurs to the wood.  For Meyer lemons, the critical temperature is 22°, while oranges can sustain serious damage to the tree after 4 hours at 24°.  The critical temperature for grapefruit trees is 26°.  Keep in mind that these are general temperature figures.  Other factors may interact with cold temperatures to influence the extent of frost damage.  For example, greater damage results when cold temperatures occur over a longer time period.  Mandarin fruit will tolerate a brief exposure to 24°, but several hours at 26° will begin to freeze the fruit.

Where a tree is planted can affect whether or not it is damaged by frost.  Trees that are growing in open areas are more likely to suffer frost damage.  Cold air tends to collect in low areas, so avoid these sites as well when planting citrus.  On the other hand, trees can benefit from reflected and reradiated heat if they are planted near walls or other structures. 

Certain cultural practices can also mitigate frost damage.  Healthy, well-irrigated trees are better able to endure freezing temperatures.   The full, leafy canopy of a healthy tree also helps shelter the fruit.  In addition, moist soil retains heat better than dry soil and can actually warm the air near the soil surface.  It is also a good idea to keep the ground around trees bare during the winter months.  Bare, moist soil is better able to absorb and reradiate heat than soil insulated with mulch, weeds, or other ground covers.  Fertilizing and pruning both encourage new growth, and delicate new growth is far more frost-sensitive than mature foliage.  Thus, pruning and fertilizing of citrus trees should occur in the spring and early summer in order to give the new vegetation time to mature and harden off before cold weather sets in.   

A light bulb (100-watt, designed for outdoor use), or Christmas lights hung in the middle of a tree can provide frost protection if the lights are the “old-fashioned” incandescent type that actually release significant heat.  When a hard freeze is predicted, watering all night with sprinklers can also protect trees from frost damage.  This only works if water is applied continuously.  If the water supply is interrupted, more damage may result than would have otherwise occurred.  Additionally, don't forget that this practice uses a lot of water and is considered inappropriate for our currently drought-stricken dry California climate.

Frost-sensitive young trees can be protected by wrapping them with insulating material from the ground up to the main branches.  In frost-prone areas, you might also consider covering trees that are one to three years old entirely, using a light material to trap heat being radiated by the ground.  A frame or stakes should be used to minimize contact between the cover and leaves because ice may form where the cover touches any leaves.  Sheets, burlap, or tarps are a better choice of cover material than plastic because plastic transfers more heat and if leaves come in contact with it they are more likely to freeze.  The cover should extend as close to the ground as possible and be removed the next morning after the temperature rises. 

If trees do show signs of frost damage, resist the urge to prune out “dead” wood in the early spring.  Allow a few months for the trees to recover with the return of warm weather.   Once new growth appears, the actual extent of the frost damage will be apparent and frost-killed branches can be removed without accidentally pruning out living material.

For more information download the free UC ANR publication 8100 on Frost Protection for Citrus and Other Subtropicals.

UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area, visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu (preferred) or call (530) 538-7201.

In keeping with the Patrick Ranch Museum's mission to enhance “people's understanding and appreciation of our community's rich agricultural heritage,” a half-acre plot planted in heirloom almond varieties is situated between the Museum's entry road and the Master Gardener Demonstration Garden. Joseph Connell, along with Susan Donahue (both instrumental in establishing the Master Gardener Program in our county), were the masterminds behind the orchard. Real Dirt recently interviewed Connell about this tribute to the history of almond farming in Butte County.

Real Dirt: How did this project come about? With whom did you partner?

Joseph Connell: Susan Donohue [retired UC Cooperative Extension Director in Butte County, and Patrick Ranch Museum Board Member] at Patrick Ranch expressed interest in featuring an historical almond orchard on the Ranch property. As the UCCE almond Farm Advisor, I agreed to work on the project with them. I used my contacts with almond growers and with the almond variety collection at UC Davis to locate budwood for each of the varieties. Budwood consists of short lengths of young branches with buds suitable for budding into a rootstock to create a tree of a particular variety. Nancy Fowler Johnson of Fowler Nursery (an orchard tree nursery in Newcastle, CA) agreed to support the project by propagating and donating enough trees of each of the varieties I included in the demonstration orchard.

RD: How and why did you choose the varieties you planted?

JC: I selected varieties that were most popular in the almond industry prior to 1900. Varieties planted here represent the foundational introduction period of the California almond industry from 1850 to 1900. Earliest plantings were of varieties such as Languedoc from the province of the same name in southern France. Languedoc originally produced poorly due to a lack of understanding of the need for cross pollination. The other varieties in this historical orchard were selected by early agricultural pioneers from amongst seedlings planted in California. They became the foundation of the California almond industry.

Nonpareil remains the leading variety in the California almond industry accounting for 39% of the total acreage in 2019.  It is also the most valuable nut in dollars per pound returned to the grower. Breeders have been trying to match its quality for decades and haven't achieved that yet. The Peerless variety and a couple of others still have a small residual acreage in a few commercial orchards although improved varieties are widespread in today's orchards.

Specific varieties planted at Patrick Ranch, the year they were introduced into California production, and their original source include:   

Row	Variety	Year Introduced	Origin
1	Ne Plus Ultra	1879	A. T. Hatch, Suisun, CA
2	I.X.L.	1879	A. T. Hatch, Suisun, CA
3	Peerless	1895	Wilson Treat, Colusa, CA
4	Nonpareil	1879	A. T. Hatch, Suisun, CA
5	Bidwell's Mammoth	1881	Bidwell Ranch, Chico, CA
6	Drake	1880	H. C. Drake, Suisun, CA
7	Languedoc	1853	Languedoc Province, France

Current statistics as of 2019: Nonpareil, the State's main variety, has 344,151 acres standing; Drake, 110 acres; Ne Plus Ultra, 1,647 acres; Peerless, (a few acres are still planted each year) 4,140 acres; while Bidwell, I.X.L., and Languedoc, are no longer listed by name in the 2019 Almond Acreage Report and may have passed into history. 

RD: Was the stock hard to find?

JC: Trees were either available through the nursery directly, propagated by the nursery with budwood from the UC Davis collection, or in the case of the Bidwell variety, from a local grower, Randy Meline, who had maintained a tree of that Bidwell Ranch selection. I believe the nursery attempted to propagate ten trees of each variety. They delivered enough trees to plant the orchard with five trees of each variety.  The eastern three rows were planted with four trees of each.   

RD: Have all of the original trees survived?

JC: One Peerless tree on the south end of the row at Patrick Ranch died from gopher damage and a new Peerless tree was replanted several years ago on Lovell peach rootstock by Nick Bertagna [a third-generation Butte County farmer, as well as the retired UCCE 4-H Program Representative.]

RD: When were the trees planted? How far apart and why?

JC: Susan and I talked about moving the project forward in 2009. I located budwood, lined up the nursery as a cooperating partner, and the nursery propagated the trees in spring 2010. The trees were budded on ‘Hansen 536' peach/almond hybrid rootstock, which is the most drought tolerant of the currently available rootstocks.  This rootstock has characteristics similar to the almond rootstock that would have been used prior to 1900. Bare root trees were dug from the nursery the following winter and, as a demonstration orchard, the one half-acre block was planted on February 21, 2011 to a single row of each variety. The early blooming varieties are planted mostly to the west of Nonpareil and the late blooming varieties are planted on the east end.    Trees were planted in north-south rows so that visitors could walk along the north end of the rows and see each of the varieties. A relatively wide 25-foot square planting (70 trees/acre) was used since peach/almond hybrid rootstock will produce large trees similar to those on almond rootstock (current commercial orchards in the Sacramento valley are often planted at around 130 trees/acre on a peach/plum hybrid rootstock).

RD: What is the anticipated “life” of this orchard?

JC: As long as the orchard is harvested traditionally by knocking nuts off with poles, and not trunk-shaken mechanically, I would expect that it would have a lifetime of at least 30-40 years. It could be there even longer; for a long, long time was the Patrick Ranch's plan.

RD: What are the maintenance goals/requirements for these trees? Harvest goals?

JC: The first-year tree training was done by me and the early pruning/training and thinning of some crowded limbs was done by Nick Bertagna. Since it is not a commercial orchard, it is expected there will be minimal fertilization and spraying and not a lot of maintenance required.

The Patrick Ranch had hoped to be able to harvest some nuts and possibly sell them in their store or at public events as heirloom varieties. Unfortunately, the ground squirrels living happily in the adjacent oak grove have done most of the harvesting...at least, the last time I checked.

RD: What can we learn from this project?

JC: The half- acre orchard is mainly there to feature one of the early crops farmed in the Chico area and to preserve the heirloom varieties. Butte County was the number one county in almond production in the middle of the last century. It was the fourth largest county in almond production as recently as 1980. Now however, Butte County produces as many almonds as it ever did, but it currently accounts for only about 3% of the State's almond production due to the vast almond acreage expansion in the San Joaquin Valley.

RD: Will there be (have there been) maintenance, harvest, etc. demonstrations for the public?

JC: There have not been such demonstrations for the public to this point. A harvesting demonstration of how it used to be done using tarps, an almond maul, and bamboo poles could be held in conjunction with other events at harvest time.

Thanks to Connell, Donahue, and all the others involved in creating this living testament to the importance of the almond crop to Butte County's history and its current local economy.

UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area, visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu (preferred) or call (530) 538-7201.