Show Notes
Garden book author and citrus expert Lance Walheim, is a big proponent of growing citrus trees in containers. We discuss his techniques in today’s podcast, along with shameless plugs for his new book, “Citrus: A Gardeners’ & Fruit Lovers’ Guide.” For those of you in a hurry, here are some of the important points we touch on in the podcast: Choose compact citrus varieties for containers — Meyer lemon, kumquat, calamondin, and Bearss limes are ideal; avoid vigorous types like Lisbon lemon or grapefruit, which will quickly outgrow most pots. Upgrade container size gradually When repotting, go up only one size at a time (e.g., sleeve → 10-gallon → 15-gallon → half barrel). Transplanting immediately from the nursery pot to an oversized container can hold excess moisture around the roots and can cause rot. Prioritize drainage above everything else Check that your container has multiple drain holes (at least 4–5 for a half barrel, ½-inch diameter or larger), and drill additional side holes if needed. Raise your container off the ground Set pots on bricks, boards, or a furniture dolly to keep drain holes clear, prevent roots escaping into the native soil, and allow the bottom of the pot to dry properly. If setting pots in catch dishes, don’t let them hold standing water. Use quality commercial potting mix, not backyard soil Garden soil may compact easily, drain poorly, and can introduce pathogens. Consider amending potting mix with perlite, builder’s sand, or pumice for improved aeration, keeping in mind this will cause it to dry out faster. Avoid dark-colored pots in hot climates Black plastic containers in full sun can heat soil to 120–130°F on warm days, killing roots. Use fabric pots, light-colored containers, or nest a dark pot inside a larger one filled with mulch for insulation. Surrounding the citrus pot with other pots can help keep the citrus roots cooler. Fertilize consistently and at a diluted strength Use a liquid or water-soluble citrus fertilizer every two to four weeks. Make sure it contains not just nitrogen but also phosphorus, potassium, and micronutrients like iron, zinc, and manganese. Leach the soil every one to two months Run water slowly through the entire pot multiple times to flush out salt buildup. A white mineral ring around the pot is a sign salts have accumulated. Use a moisture meter to check watering needs Finger-testing the surface is unreliable in root-bound pots; a moisture meter tells you conditions 12 inches down where it matters. Mulch the top of the container A thin layer of bark chips or compost slows moisture loss and protects surface roots. Keep mulch away from the trunk. Transition plants indoors and outdoors gradually Over one to two weeks, move the pot into progressively shadier spots before bringing it inside, and reverse the process in spring. Expect some leaf drop indoors; a bloom cycle usually follows. Treat for pests before moving indoors Apply Neem oil or Spinosad before bringing the tree inside to prevent scale or whiteflies from establishing. Avoid applying oil when temperatures are above 85–90°F. Prune to maintain size and airflow Keep the tree’s center open for air circulation, remove crossing branches, and cut back vigorous shoots. Do major work (including root pruning, if necessary) in winter, the least stressful time. Look for Flying Dragon rootstock if you want a true dwarf This trifoliate orange rootstock keeps trees to 5–6 feet and is well-suited to long-term container growing, though it can be hard to find. Buy only from reputable nurseries Asian citrus psyllid and HLB disease have spread to all major citrus states. Purchasing certified trees (rather than propagating cuttings from friends) is the safest way to avoid bringing home an infestation.
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More from Beyond the Garden Basics
The high points of our chat with Lance Walheim in today’s podcast: * Pick the right variety first. Sweet types like navel oranges struggle indoors, so go with acidic fruit that ripens with less heat. * Meyer lemons, kumquats, Bearss limes and calamondins are the best bets. They’re compact, bloom often and fit in containers. * Regular lemons and grapefruit can survive indoors, but don’t expect much edible fruit from them. * Moving trees in and out is workable, but you need a transition period. Going outside in spring, start in shade after the last frost and increase light over several weeks. Coming inside, reverse the process and reduce light gradually. * The shock is real. Outdoor humidity can top 50 or 60 percent, while a heated house can drop to around 10 percent.
Redwood Barn Nursery owner Don Shor of Davis, California and myself finally got around to putting the 2026 Tomato season to bed…except for the ones that are hanging on for dear life. In today’s podcast, we sing the high notes and low notes of our tomato growing efforts this year, with lots of gardening advice thrown in for good measure. How was your tomato season? Any favorites? Any failures? Any surprises? Let us know in the comments, and be sure to mention where you were doing your gardening this summer. One of the first to comment was Keith, located in the eastern portion of the San Francisco Bay area. He actually commented before the tomato season was ending: “When you two get together to talk about the 2026 tomato season, I'd like to put in a good word for my San Marzano tomato harvest in Contra Costa County. I had a good crop, mostly because the weather wasn't too hot. Tomorrow is sauce-making day! I have a set-up that lets me cook outside.” There’s a complete, human-edited transcript of the podcast near the bottom of this newsletter. Here are the main points of our podcast conversation:
In today’s podcast, I tell a long, drawn out story about what happened the night before my wedding in 1980. Yes, it is a garden story, about the Cecile Bruner rose. But, we quickly turn to a chat with Ben Hanna of heirloomroses.com, who describes how he and his wife came to own the company after leaving corporate life over a decade ago. He says their shared love of gardening and roses, plus the chance to work closer to family, made the business a good fit. He also notes that all five of his children have worked at the nursery in different roles. In the newsletter, it's a list of the best roses for fall blooming color!
In today’s podcast, we talk with Mark Seibert of Sturdi-Built greenhouses in Oregon. The interview covers key considerations for first-time greenhouse buyers, including choosing the right site, with emphasis on sunlight, southern exposure when possible, and local hazards such as trees or lawn equipment. It also discusses heat control and utilities, recommending ventilation, shade cloth, fans, water access, and electrical service with safety protections. Seibert also explains that lean-to greenhouses can work if the roof pitch and site conditions fit, and says a well-built greenhouse can last 20 to 30 years. Growing Hobby Greenhouse Tomatoes in the Winter If you really want to demonstrate to your friends what a great investment your greenhouse is, nothing beats serving them home grown tomatoes...on New Year’s Day. Here’s What You’ll Need to Grow Greenhouse Tomatoes for the Winter and Spring:
The discussion in today’s podcast focuses on pumpkins. Warren Roberts, Superintendent Emeritus of the UC Davis Arboretum, explains that the pumpkin is botanically a fruit, though it is usually eaten as a vegetable. He says the plant belongs to the genus Cucurbita, which is native to the Americas, especially Mexico and the Andes. He describes pumpkin types and notes that many large pumpkins are hybrids, often involving Cucurbita maxima. He contrasts these with the smaller typical pumpkin species, Cucurbita pepo. The conversation also covers the origin of jack-o’-lanterns, whose purpose, Roberts says, came from hollowed-out turnips or rutabagas used to carry coals before matches were available (a handy skill to remember when AI takes over). Short of Garden Room? Grow Mini-Pumpkins! Admittedly, I got a late start on planting pumpkins this year: in early summer (the 4th of July weekend), and I had only one raised garden bed, 4 feet by 8 feet, still available. So, I planted three pumpkin seeds that would eventually produce medium sized pumpkins, the “Jack O’ Lantern” variety, a fruit that gets about 15 pounds. I won’t make that mistake again. Fast-forward three months, and I have a jungle of green vines from those three seeds that have escaped the confines of the raised bed and are now proceeding to swallow the trunks of my adjacent fruit trees. And it looks like the end-result for Halloween decorations will be only four or five medium sized pumpkins. Not much production, considering the sprawl of the vines. And three of them are still green, making me wonder if they will be nice orange orbs ready for carving at the end of the month. Fortunately for gardeners, many seed catalogs and nursery seed racks feature pumpkin varieties that mature in about 90 days and don’t do much sprawling: the miniature pumpkins. There are several advantages to growing pumpkins that weigh less than a pound: quicker maturity, a smaller footprint, and versatility in shapes, color, and uses.