WASHINGTON — When the U.S. National Arboretum’s handsome modernist administration building is reopened in time for spring, I hope the $9 million renovation will be symbolic of a larger renewal at the institution.

That’s also the keen desire of many others, including its director, Colien Hefferan, who is planning to unveil something even more vital to the arboretum when the first crocuses burst forth: a strategic plan for its future.

The arboretum occupies one of the largest open spaces in the nation’s capital — 446 acres — and functions on many levels. It is the horticultural research arm of the Agricultural Research Service (part of the Agriculture Department), a leafy riverside park for residents and a place for garden lovers to commune with flora.

It is a priceless “green” asset in an area of the city that has often been neglected, and it is also one of the 10 most popular botanical parks in the United States. But it is also one afflicted in recent years by a chronic underfunding for staff, operations and maintenance, forcing supporters to go directly to Congress in search of budget add-ons. (The administration building renovation was funded by stimulus grants.)

In our age of deficits and political deadlock — the recent “fiscal cliff” deal notwithstanding — many government agencies have been patching what they do for years: The national park system is suffering from more than $10 billion worth of deferred maintenance, according to a 2011 report.

But for those of us who have seen the arboretum lurch from one money crisis to another for so long, the idea of a clearer path forward is surely welcome.

The problem came to a head in 2010 when the loss of a relatively small endowment forced managers to propose ripping out the arboretum’s popular azalea and boxwood collections to save money. The resulting furor predated Hefferan’s appointment, but it reinforced her desire to assemble a group of 12 experts in plant science and education (including Hefferan, the arboretum’s first female director) to find a plan.

In a draft that should be finalized in March, the panel has concluded that the arboretum needs to emphasize its least-understood function, as a laboratory where scientists develop better trees and shrubs. Hybridizers have sought to find woody plants that have a longer season of bloom, a showier berry, a more compact size for smaller gardens. They have also eyed the needs of the commercial grower, with plants that are easy to propagate and widely adaptable. They have also sought to breed against pests and disease — the arboretum has virtually reinvented the crape myrtle but did so largely to rid it of powdery mildew.

The ecological benefits of horticulture are now more pressing, and alluring, than ever. And the imperative today might be in breeding plants that can cope with more drought, more heat and fewer pesticides and at the same time not invade areas where they are not wanted.

In that sense, any reinforcement of its core scientific mission provides a golden opportunity for the arboretum in an age when plants are needed to shade and oxygenate the planet, cover green roofs, hold and filter storm water, and generally mitigate climate change.

The word “horticulture” used to be preceded by “ornamental” or, in the old days, “decorative.” In the draft report, I see a new term, “environmental horticulture.”

The emphasis is good, as long as the arboretum remains — and further becomes — a place where people can also luxuriate in the beauty of flora. The planet might need healing, but so do our souls from time to time.

One of the objectives of the strategic plan is to provide “a coherent link” between garden displays and the arboretum’s science “to connect the garden aesthetic to discovery.”

A taste of this will come this year with the arrival of a display of turf grass and ornamental grass varieties developed by ARS scientists.

“Many of the most esteemed botanic gardens in the world have that three-legged stool of research, education and garden display,” said Paul Meyer, a member of the panel and director of the Morris Arboretum in Philadelphia. “If you get it right, they support one another.”

But to achieve a better footing to do this, the panel says, the arboretum needs to forge stronger partnerships with other entities. (Its friends group, FONA, has long supplemented the arboretum’s work and provided a direct channel to Congress.)

There could be ways to expand FONA’s current role, Hefferan said, as well as strengthen the arboretum’s ability to get funds from private entities. One idea is to jump into the lucrative wedding-venue market, an approach used by other botanical gardens for years.

Another is to create a center for scientific symposia and generally expand the arboretum’s role in convening plant scientists.

The plan itself, of course, doesn’t generate funds for a cash-strapped institution. But it lays the groundwork, Meyer said.

“What you need is the leadership and the plan in place to say, ’Here’s who we are, this is what we are going to do, and we need help to do it,’ “ he said. “Whether it’s the help of Congress or private individuals or foundations, the strong strategic plan is central to raising money.”