Seasonal Maintenance Calendars

Winter: December through February

This is the low demand period and the right time for structural work. Irrigation should be substantially reduced or shut off entirely during rain periods, and this is when systems running unchanged from summer waste the most water.

• Reduce irrigation schedules substantially or shut off during rain
• Perform tree pruning while structure is visible and most species are least active
• Apply pre-emergent in late winter ahead of spring weed germination
• Complete major cleanups from the fall and winter leaf drop
• Plan and schedule the coming year's programs and capital work

Spring: March through May

Growth accelerates and service frequency needs to increase with it. This is also when the year's irrigation performance is determined, because a system that starts the season with unrepaired failures will not keep up once heat arrives.

• Complete irrigation start up with full zone by zone inspection and repair
• Increase mowing frequency as growth accelerates
• Begin the main fertilization program
• Refresh mulch in all beds before summer heat arrives
• Rotate to warm season color at entries and high visibility zones
• Address weeds that escaped the pre-emergent application

Summer: June through September

Peak demand. The priorities are keeping plant material alive through heat stress and keeping irrigation correct, because this is when a scheduling error produces visible plant loss within days rather than weeks.

• Monitor irrigation closely and adjust for heat waves as they occur
• Maintain weekly service on high visibility and fast growing areas
• Watch for heat stress and pest pressure, both of which spike now
• Prune palms ahead of the fall Santa Ana wind season
• Rotate color more frequently, since display life is shorter in heat
• Avoid heavy pruning on stressed material during peak heat

Fall: October through November

The transition period and the most consequential month for weed pressure. Fall pre-emergent timing determines how much hand weeding the property needs through winter and early spring.

• Apply fall pre-emergent ahead of the winter weed germination flush
• Begin reducing irrigation as demand drops
• Complete tree assessment ahead of the wind and rain season
• Address any erosion exposure on slopes before winter rain
• Clear drains, inlets, and catch basins ahead of the rain season
• Rotate to cool season color
• Begin the leaf drop cleanup cycle

Why a Southern California calendar looks wrong to everyone else

Most landscape calendars are written for climates with a real winter. They assume a dormant season where almost nothing happens, and a frantic spring when everything starts at once.

Neither is true here. Growth slows in winter but does not stop, so there is no month where a property can be left alone. Spring is less of a starting gun and more of a gradual acceleration.

The seasons that actually matter here are different ones. The dry stretch from June to October is the hard season, not winter. The short rainy window from December to March is when planting establishes cheaply, and it is the one people miss because it feels like the off season.

months of growth, at varying speed

12months of growth, at varying speed

months of reliable dry weather to plan around

5months of reliable dry weather to plan around

months when nothing needs doing

0months when nothing needs doing

The two windows that matter most

Two short periods carry more weight than the rest of the year combined, and both are easy to miss because neither one looks urgent.

The first is late autumn, roughly October and November. Planting done then goes into cool soil with rain ahead of it, and establishes on a fraction of the water it would need in spring. The same planting in May needs irrigation all summer to survive its first year.

The second is late winter, roughly February. It is the last comfortable window for structural tree work before growth starts, and the point where irrigation should be checked and reprogrammed before demand climbs. Work done in February is calm. The same work in June is an emergency.

Building a calendar for your own property

A generic calendar gets you most of the way. The last part depends on your site, and it takes about an hour to work out.

Start from what actually grows there, then adjust for exposure and use. An inland site runs hotter and dries faster than a coastal one. A shaded courtyard barely grows in winter. A high traffic entry needs attention on a rhythm that has nothing to do with the season.

1. List the turf and major plant types on the property
2. Mark which areas are inland, coastal, sunny, or shaded, because they run on different clocks
3. Set mowing frequency by season for each turf area, not one rate for the year
4. Fix the two windows first: autumn planting and late winter irrigation and tree work
5. Put the annual items on named months, so they cannot drift
6. Review it once a year against what actually happened

What slips, and how to stop it

Calendars fail in a predictable way. The weekly items happen because someone notices when they do not. The annual items slip because nothing visible changes on the day they are missed.

By the second year, the annual tier has often quietly disappeared, and nobody can say when. That is how a property goes from maintained to declining without a single decision being made.

The fix is not a better calendar. It is attaching the annual items to a month and a report line, so a missed one shows up in writing rather than in the landscape two years later.